{"id":12642,"date":"2026-02-12T06:26:40","date_gmt":"2026-02-12T04:26:40","guid":{"rendered":"https:\/\/store.algosyntax.com\/?post_type=asx-lms-tutorial-cpt&#038;p=12642"},"modified":"2026-03-09T03:25:21","modified_gmt":"2026-03-09T01:25:21","slug":"ue5-stall-detector-false-gui-stalls-exception-thrown-ntdll-dll","status":"publish","type":"asx-lms-tutorial-cpt","link":"https:\/\/store.algosyntax.com\/tutorials\/unreal-engine\/ue5-stall-detector-false-gui-stalls-exception-thrown-ntdll-dll\/","title":{"rendered":"UE5 Stall Detector | False GUI Stalls | Exception Thrown ntdll.dll"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"12642\" class=\"elementor elementor-12642\" data-elementor-post-type=\"asx-lms-tutorial-cpt\">\n\t\t\t\t<div class=\"elementor-element elementor-element-a3e829d e-flex e-con-boxed e-con e-parent\" data-id=\"a3e829d\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-62f497d elementor-widget elementor-widget-heading\" data-id=\"62f497d\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Unreal Engine\u2019s Stall Detector As The Core Issue<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0df968e elementor-widget elementor-widget-text-editor\" data-id=\"0df968e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"427\" data-end=\"530\">When integrating external GUI systems (such as VST plugin editors) into Unreal Engine, you may observe:<\/p><ul data-start=\"532\" data-end=\"739\"><li data-start=\"532\" data-end=\"591\"><p data-start=\"534\" data-end=\"591\">Visual Studio breaking with <code data-start=\"562\" data-end=\"591\">0xC0000005 Access Violation<\/code><\/p><\/li><li data-start=\"592\" data-end=\"633\">Call stacks containing &#8220;<code data-start=\"617\" data-end=\"633\">StackWalk\"<\/code><\/li><li data-start=\"592\" data-end=\"633\"><p data-start=\"594\" data-end=\"633\">Threads containing <code data-start=\"617\" data-end=\"633\">StallDetectorThread<\/code><\/p><\/li><li data-start=\"634\" data-end=\"672\"><p data-start=\"636\" data-end=\"672\">Stack walking via <code data-start=\"654\" data-end=\"672\">RtlVirtualUnwind<\/code><\/p><\/li><li data-start=\"673\" data-end=\"702\"><p data-start=\"675\" data-end=\"702\">Breaks only while debugging<\/p><\/li><li data-start=\"703\" data-end=\"739\"><p data-start=\"705\" data-end=\"739\">No crash when debugger is detached<\/p><\/li><\/ul><p data-start=\"741\" data-end=\"766\">This is not a real crash.<\/p><p data-start=\"768\" data-end=\"958\">This is Unreal Engine\u2019s <strong data-start=\"792\" data-end=\"886\">Stall Detector misclassifying valid external modal\/message-loop activity as a thread stall<\/strong>, followed by the debugger interrupting during diagnostic stack capture.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2e41774 elementor-widget elementor-widget-image\" data-id=\"2e41774\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"1101\" height=\"911\" src=\"https:\/\/store.algosyntax.com\/wp-content\/uploads\/tutorials\/unreal-engine\/stalldetector-crash.png\" class=\"attachment-medium size-medium wp-image-12650\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-68d17e9 e-flex e-con-boxed e-con e-parent\" data-id=\"68d17e9\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-19d0e61 elementor-widget elementor-widget-heading\" data-id=\"19d0e61\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">What the Stall Detector Actually Does<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-10fcc35 elementor-widget elementor-widget-text-editor\" data-id=\"10fcc35\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"1106\" data-end=\"1214\">The Stall Detector is an instrumentation system used by Unreal to identify threads that appear unresponsive.<\/p><p data-start=\"1216\" data-end=\"1424\">It works by wrapping critical engine scopes with timers. If execution exceeds a configured budget (often ~2 seconds), Unreal assumes the thread may be deadlocked and attempts to gather diagnostic information.<\/p><p data-start=\"1426\" data-end=\"1438\">Importantly:<\/p><p data-start=\"1440\" data-end=\"1500\"><strong data-start=\"1440\" data-end=\"1479\">A stall is not automatically a bug.<\/strong><br data-start=\"1479\" data-end=\"1482\" \/>It is a heuristic.<\/p><p data-start=\"1502\" data-end=\"1540\">The engine cannot distinguish between:<\/p><ul data-start=\"1542\" data-end=\"1631\"><li data-start=\"1542\" data-end=\"1575\"><p data-start=\"1544\" data-end=\"1575\">a thread that is truly frozen<\/p><\/li><li data-start=\"1576\" data-end=\"1631\"><p data-start=\"1578\" data-end=\"1631\">a thread that is busy inside an external modal loop<\/p><\/li><\/ul><p data-start=\"1633\" data-end=\"1669\">So it errs on the side of reporting.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-9ffa541 elementor-widget elementor-widget-code-highlight\" data-id=\"9ffa541\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"code-highlight.default\">\n\t\t\t\t\t\t\t<div class=\"prismjs-default copy-to-clipboard \">\n\t\t\t<pre data-line=\"\" class=\"highlight-height language-cpp line-numbers\">\n\t\t\t\t<code readonly=\"true\" class=\"language-cpp\">\n\t\t\t\t\t<xmp>SCOPE_STALL_COUNTER(SomeScope, TimeBudgetSeconds)\n\n<\/xmp>\n\t\t\t\t<\/code>\n\t\t\t<\/pre>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-945c48c elementor-widget elementor-widget-code-highlight\" data-id=\"945c48c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"code-highlight.default\">\n\t\t\t\t\t\t\t<div class=\"prismjs-default copy-to-clipboard \">\n\t\t\t<pre data-line=\"\" class=\"highlight-height language-cpp line-numbers\">\n\t\t\t\t<code readonly=\"true\" class=\"language-cpp\">\n\t\t\t\t\t<xmp>\n\/\/eg main Engine loop, gives your process 2 seconds to respond\nvoid FEngineLoop::Tick()\n{\n\tSCOPED_NAMED_EVENT_TEXT(\"FEngineLoop::Tick\", FrameColor);\n\tSCOPE_STALL_COUNTER(FEngineLoop::Tick, 2.0);\n}<\/xmp>\n\t\t\t\t<\/code>\n\t\t\t<\/pre>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0274ce1 elementor-widget elementor-widget-text-editor\" data-id=\"0274ce1\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"1239\" data-end=\"1305\">If a scope exceeds its time budget (often ~2 seconds), the engine:<\/p><ol data-start=\"1307\" data-end=\"1423\"><li data-start=\"1307\" data-end=\"1342\"><p data-start=\"1310\" data-end=\"1342\">Assumes the thread may be stuck.<\/p><\/li><li data-start=\"1343\" data-end=\"1391\"><p data-start=\"1346\" data-end=\"1391\">Attempts to capture that thread\u2019s call stack.<\/p><\/li><li data-start=\"1392\" data-end=\"1423\"><p data-start=\"1395\" data-end=\"1423\">Logs diagnostic information.<\/p><\/li><\/ol><p data-start=\"1425\" data-end=\"1477\">This is meant to catch deadlocks and infinite loops.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-64493e2 e-flex e-con-boxed e-con e-parent\" data-id=\"64493e2\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-0c71bbe elementor-widget elementor-widget-heading\" data-id=\"0c71bbe\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Why External UI Systems Trigger False Stalls<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-cc17e64 elementor-widget elementor-widget-text-editor\" data-id=\"cc17e64\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"1724\" data-end=\"1821\">Many UI frameworks \u2014 including plugin GUIs \u2014 do not follow Unreal\u2019s frame-driven execution model.<\/p><p data-start=\"1823\" data-end=\"1843\">Instead, they often:<\/p><ul data-start=\"1845\" data-end=\"1963\"><li data-start=\"1845\" data-end=\"1864\"><p data-start=\"1847\" data-end=\"1864\">run modal loops<\/p><\/li><li data-start=\"1865\" data-end=\"1900\"><p data-start=\"1867\" data-end=\"1900\">pump their own Windows messages<\/p><\/li><li data-start=\"1901\" data-end=\"1931\"><p data-start=\"1903\" data-end=\"1931\">block until a popup closes<\/p><\/li><li data-start=\"1932\" data-end=\"1963\"><p data-start=\"1934\" data-end=\"1963\">perform synchronous UI work<\/p><\/li><\/ul><p data-start=\"1965\" data-end=\"1982\">Examples include:<\/p><ul data-start=\"1984\" data-end=\"2082\"><li data-start=\"1984\" data-end=\"2002\"><p data-start=\"1986\" data-end=\"2002\">dropdown menus<\/p><\/li><li data-start=\"2003\" data-end=\"2022\"><p data-start=\"2005\" data-end=\"2022\">preset browsers<\/p><\/li><li data-start=\"2023\" data-end=\"2039\"><p data-start=\"2025\" data-end=\"2039\">file dialogs<\/p><\/li><li data-start=\"2040\" data-end=\"2052\"><p data-start=\"2042\" data-end=\"2052\">tooltips<\/p><\/li><li data-start=\"2053\" data-end=\"2082\"><p data-start=\"2055\" data-end=\"2082\">blocking progress windows<\/p><\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d969f5e elementor-widget elementor-widget-text-editor\" data-id=\"d969f5e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"2084\" data-end=\"2158\">From Unreal\u2019s perspective, the monitored thread stops ticking engine code.<\/p><p data-start=\"2160\" data-end=\"2186\">So the detector concludes:<\/p><blockquote data-start=\"2188\" data-end=\"2215\"><p data-start=\"2190\" data-end=\"2215\">\u201cThread appears stalled.\u201d<\/p><\/blockquote><p data-start=\"2217\" data-end=\"2274\">But the thread is actually busy \u2014 just not inside Unreal.<\/p><p data-start=\"2276\" data-end=\"2309\">This is a classic false positive.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-d0fe2e3 e-flex e-con-boxed e-con e-parent\" data-id=\"d0fe2e3\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-0fdd89b elementor-widget elementor-widget-heading\" data-id=\"0fdd89b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Where the Access Violation Comes From<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-951cecb elementor-widget elementor-widget-text-editor\" data-id=\"951cecb\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"2357\" data-end=\"2439\">After detecting a stall, Unreal attempts to capture a stack trace for diagnostics.<\/p><p data-start=\"2441\" data-end=\"2612\">Stack walking through native binaries \u2014 especially optimized or protected ones \u2014 is not always clean. During this process Windows may raise a structured exception such as:<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-f3853c2 elementor-widget elementor-widget-code-highlight\" data-id=\"f3853c2\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"code-highlight.default\">\n\t\t\t\t\t\t\t<div class=\"prismjs-default copy-to-clipboard \">\n\t\t\t<pre data-line=\"\" class=\"highlight-height language-cpp line-numbers\">\n\t\t\t\t<code readonly=\"true\" class=\"language-cpp\">\n\t\t\t\t\t<xmp>0xC0000005 Access Violation\n<\/xmp>\n\t\t\t\t<\/code>\n\t\t\t<\/pre>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1a33961 elementor-widget elementor-widget-image\" data-id=\"1a33961\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"1101\" height=\"911\" src=\"https:\/\/store.algosyntax.com\/wp-content\/uploads\/tutorials\/unreal-engine\/stalldetector-crash.png\" class=\"attachment-medium size-medium wp-image-12650\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-756cc77 elementor-widget elementor-widget-text-editor\" data-id=\"756cc77\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"2651\" data-end=\"2706\">These exceptions are frequently <strong data-start=\"2683\" data-end=\"2705\">handled internally<\/strong>.<\/p><p data-start=\"2708\" data-end=\"2835\">However, when Visual Studio is configured to break on thrown Win32 exceptions, it interrupts execution before the handler runs.<\/p><p data-start=\"2837\" data-end=\"2895\">This makes the situation look like a crash when it is not.<\/p><p data-start=\"2897\" data-end=\"2952\">Detach the debugger, and everything continues normally.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-be14c97 e-flex e-con-boxed e-con e-parent\" data-id=\"be14c97\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-8e63b23 elementor-widget elementor-widget-heading\" data-id=\"8e63b23\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Important: This Is Not Specific to VST Plugins<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-373150e elementor-widget elementor-widget-text-editor\" data-id=\"373150e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"3009\" data-end=\"3101\">VST GUIs are simply a very visible example because they ship with full custom UI frameworks.<\/p><p data-start=\"3103\" data-end=\"3140\">But the same behavior can occur with:<\/p><ul data-start=\"3142\" data-end=\"3268\"><li data-start=\"3142\" data-end=\"3166\"><p data-start=\"3144\" data-end=\"3166\">native Win32 dialogs<\/p><\/li><li data-start=\"3167\" data-end=\"3187\"><p data-start=\"3169\" data-end=\"3187\">external editors<\/p><\/li><li data-start=\"3188\" data-end=\"3215\"><p data-start=\"3190\" data-end=\"3215\">proprietary UI toolkits<\/p><\/li><li data-start=\"3216\" data-end=\"3242\"><p data-start=\"3218\" data-end=\"3242\">embedded browser views<\/p><\/li><li data-start=\"3243\" data-end=\"3268\"><p data-start=\"3245\" data-end=\"3268\">platform file pickers<\/p><\/li><\/ul><p data-start=\"3270\" data-end=\"3309\">The root cause is the mismatch between:<\/p><p data-start=\"3311\" data-end=\"3404\"><strong data-start=\"3311\" data-end=\"3354\">Unreal\u2019s tick-based thread expectations<\/strong><br data-start=\"3354\" data-end=\"3357\" \/>and<br data-start=\"3360\" data-end=\"3363\" \/><strong data-start=\"3363\" data-end=\"3404\">externally-driven modal\/message loops<\/strong><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-6ef90f7 e-flex e-con-boxed e-con e-parent\" data-id=\"6ef90f7\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-dba36c9 elementor-widget elementor-widget-heading\" data-id=\"dba36c9\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Confirming the Issue<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-81a90e5 elementor-widget elementor-widget-text-editor\" data-id=\"81a90e5\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"3435\" data-end=\"3456\">A quick sanity check:<\/p><p data-start=\"3458\" data-end=\"3562\">If the application runs correctly when the debugger is detached, you are not dealing with a fatal crash.<\/p><p data-start=\"3564\" data-end=\"3627\">You are observing debugger behavior during a handled exception.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-14b29c1 e-flex e-con-boxed e-con e-parent\" data-id=\"14b29c1\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-6a22afc elementor-widget elementor-widget-heading\" data-id=\"6a22afc\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Solution Options<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-9b481ca elementor-widget elementor-widget-text-editor\" data-id=\"9b481ca\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"3654\" data-end=\"3716\">There are three practical solutions, plus one advanced option.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-787c67b e-flex e-con-boxed e-con e-parent\" data-id=\"787c67b\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-06d449e elementor-widget elementor-widget-heading\" data-id=\"06d449e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Solution 1 \u2014 Pause the Stall Detector (When You Control the Blocking Scope)<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-91ab35f elementor-widget elementor-widget-text-editor\" data-id=\"91ab35f\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"4624\" data-end=\"4665\">Unreal provides an explicit &#8220;ignore stall detector&#8221; macro.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-01cd46c elementor-widget elementor-widget-code-highlight\" data-id=\"01cd46c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"code-highlight.default\">\n\t\t\t\t\t\t\t<div class=\"prismjs-default copy-to-clipboard \">\n\t\t\t<pre data-line=\"\" class=\"highlight-height language-cpp line-numbers\">\n\t\t\t\t<code readonly=\"true\" class=\"language-cpp\">\n\t\t\t\t\t<xmp>SCOPE_STALL_DETECTOR_PAUSE();\n<\/xmp>\n\t\t\t\t<\/code>\n\t\t\t<\/pre>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2d7d364 elementor-widget elementor-widget-text-editor\" data-id=\"2d7d364\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"4706\" data-end=\"4728\">This tells the engine:<\/p><blockquote data-start=\"4730\" data-end=\"4819\"><p data-start=\"4732\" data-end=\"4819\">\u201cWe are about to perform a possibly long blocking operation in this scope {}. Do not treat this time as a stall.\u201d<\/p><\/blockquote><p data-start=\"4821\" data-end=\"4879\">Epic uses this internally when launching Slate modal loops\/windows.<\/p><p data-start=\"4881\" data-end=\"4913\">However \u2014 and this is critical \u2014<\/p><p data-start=\"4915\" data-end=\"4970\"><strong data-start=\"4915\" data-end=\"4970\">It only works if you control the scope that blocks.<\/strong><\/p><p data-start=\"4972\" data-end=\"5001\">Examples where it works well:<\/p><ul data-start=\"5003\" data-end=\"5123\"><li data-start=\"5003\" data-end=\"5038\"><p data-start=\"5005\" data-end=\"5038\">launching your own modal window<\/p><\/li><li data-start=\"5039\" data-end=\"5064\"><p data-start=\"5041\" data-end=\"5064\">blocking editor tools<\/p><\/li><li data-start=\"5065\" data-end=\"5104\"><p data-start=\"5067\" data-end=\"5104\">synchronous operations you initiate<\/p><\/li><li data-start=\"5105\" data-end=\"5123\"><p data-start=\"5107\" data-end=\"5123\">custom dialogs<\/p><\/li><\/ul><p data-start=\"5125\" data-end=\"5157\">Examples where it does NOT help:<\/p><ul><li data-start=\"5159\" data-end=\"5187\"><p data-start=\"5161\" data-end=\"5187\">plugin-created dropdowns<\/p><\/li><li data-start=\"5188\" data-end=\"5215\"><p data-start=\"5190\" data-end=\"5215\">internal UI modal loops<\/p><\/li><li data-start=\"5216\" data-end=\"5240\"><p data-start=\"5218\" data-end=\"5240\">third-party toolkits<\/p><\/li><li data-start=\"5241\" data-end=\"5270\"><p data-start=\"5243\" data-end=\"5270\">code paths you do not own or have control over<\/p><\/li><\/ul><p data-start=\"5272\" data-end=\"5324\">In those cases, you cannot wrap the blocking period.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-0afaca1 e-flex e-con-boxed e-con e-parent\" data-id=\"0afaca1\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-ff0884c elementor-widget elementor-widget-heading\" data-id=\"ff0884c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Solution 2 \u2014 Disable Breaking on Thrown Access Violations (Recommended)<\/h2>\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-f2d0bf6 e-con-full e-flex e-con e-child\" data-id=\"f2d0bf6\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-adf1d14 elementor-widget elementor-widget-text-editor\" data-id=\"adf1d14\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"3801\" data-end=\"3806\">In Visual Studio Open:<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-26b61f0 elementor-widget elementor-widget-code-highlight\" data-id=\"26b61f0\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"code-highlight.default\">\n\t\t\t\t\t\t\t<div class=\"prismjs-default copy-to-clipboard \">\n\t\t\t<pre data-line=\"\" class=\"highlight-height language-cpp line-numbers\">\n\t\t\t\t<code readonly=\"true\" class=\"language-cpp\">\n\t\t\t\t\t<xmp>Debug \u2192 Windows \u2192 Exception Settings\n<\/xmp>\n\t\t\t\t<\/code>\n\t\t\t<\/pre>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-6be5751 e-con-full e-flex e-con e-child\" data-id=\"6be5751\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-f72497f elementor-widget elementor-widget-text-editor\" data-id=\"f72497f\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"3854\" data-end=\"3861\">Locate:<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-f345bb1 elementor-widget elementor-widget-code-highlight\" data-id=\"f345bb1\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"code-highlight.default\">\n\t\t\t\t\t\t\t<div class=\"prismjs-default copy-to-clipboard \">\n\t\t\t<pre data-line=\"\" class=\"highlight-height language-cpp line-numbers\">\n\t\t\t\t<code readonly=\"true\" class=\"language-cpp\">\n\t\t\t\t\t<xmp>Win32 Exceptions \u2192 0xC0000005 Access violation\n<\/xmp>\n\t\t\t\t<\/code>\n\t\t\t<\/pre>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2f8f253 elementor-widget elementor-widget-text-editor\" data-id=\"2f8f253\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"3854\" data-end=\"3861\">You want to untick this option. This will avoid the debugger getting triggered when modal windows launch.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-539f20d elementor-widget elementor-widget-image\" data-id=\"539f20d\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"1371\" height=\"398\" src=\"https:\/\/store.algosyntax.com\/wp-content\/uploads\/tutorials\/unreal-engine\/disable-av-win32.jpg\" class=\"attachment-large size-large wp-image-12659\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-06183d3 e-con-full e-flex e-con e-child\" data-id=\"06183d3\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-7665454 elementor-widget elementor-widget-heading\" data-id=\"7665454\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Why this is safe<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3d40d81 elementor-widget elementor-widget-text-editor\" data-id=\"3d40d81\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"3978\" data-end=\"4014\">This does <strong data-start=\"3988\" data-end=\"3995\">NOT<\/strong> hide real crashes.<\/p><p data-start=\"4016\" data-end=\"4117\">Visual Studio will still break when an access violation is unhandled and would terminate the process.<\/p><p data-start=\"4119\" data-end=\"4146\">You can verify this easily:<br \/>With the option unticked try to do something illegal like this Access Violation:<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6409346 elementor-widget elementor-widget-code-highlight\" data-id=\"6409346\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"code-highlight.default\">\n\t\t\t\t\t\t\t<div class=\"prismjs-default copy-to-clipboard \">\n\t\t\t<pre data-line=\"\" class=\"highlight-height language-cpp line-numbers\">\n\t\t\t\t<code readonly=\"true\" class=\"language-cpp\">\n\t\t\t\t\t<xmp>UObject* Obj = nullptr;\nObj->GetName();\n<\/xmp>\n\t\t\t\t<\/code>\n\t\t\t<\/pre>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-375e597 elementor-widget elementor-widget-text-editor\" data-id=\"375e597\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"4200\" data-end=\"4237\">The debugger still stops immediately.<\/p><p data-start=\"4239\" data-end=\"4332\">What you are disabling is early interruption on exceptions that are later handled internally.<\/p><p data-start=\"4410\" data-end=\"4475\">Many large native systems intentionally raise handled exceptions.<\/p><p data-start=\"4477\" data-end=\"4535\">Breaking on all of them makes debugging nearly impossible.<br \/><br \/>Here&#8217;s how to confirm:<br \/>Enable ALL win32 Exceptions. Then try to launch the UE Editor, it will keep triggering a lot of exceptions itself. You can right click &#8220;Win32 Exceptions&#8221; and Reset To Default After.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-96a33f4 e-flex e-con-boxed e-con e-parent\" data-id=\"96a33f4\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-2042bf6 elementor-widget elementor-widget-heading\" data-id=\"2042bf6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Solution 3 \u2014 Detach the Debugger During UI Interaction<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-fa633f2 elementor-widget elementor-widget-text-editor\" data-id=\"fa633f2\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"5392\" data-end=\"5422\">A simple workflow improvement:<\/p><ul data-start=\"5424\" data-end=\"5513\"><li data-start=\"5424\" data-end=\"5457\"><p data-start=\"5426\" data-end=\"5457\">Attach debugger for code work<\/p><\/li><li data-start=\"5458\" data-end=\"5513\"><p data-start=\"5460\" data-end=\"5513\">Detach when stress-testing external GUI interaction<\/p><\/li><\/ul><p data-start=\"5515\" data-end=\"5590\">This avoids debugger interruption while preserving normal runtime behavior.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-1497fc0 e-flex e-con-boxed e-con e-parent\" data-id=\"1497fc0\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-1da5ac7 elementor-widget elementor-widget-heading\" data-id=\"1da5ac7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">4 \u2014 Hook Native Window Events<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0cbe77e elementor-widget elementor-widget-text-editor\" data-id=\"0cbe77e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"5721\" data-end=\"5861\">It is technically possible to monitor or intercept Win32 window events (HWND message hooks) to better coordinate with Unreal\u2019s expectations.<\/p><p data-start=\"5863\" data-end=\"5919\">For example, detecting when a popup enters a modal loop.<\/p><p data-start=\"5921\" data-end=\"5929\">However:<\/p><ul data-start=\"5931\" data-end=\"6040\"><li data-start=\"5931\" data-end=\"5950\"><p data-start=\"5933\" data-end=\"5950\">This is complex<\/p><\/li><li data-start=\"5951\" data-end=\"5972\"><p data-start=\"5953\" data-end=\"5972\">Platform-specific<\/p><\/li><li data-start=\"5973\" data-end=\"6002\"><p data-start=\"5975\" data-end=\"6002\">brittle across frameworks<\/p><\/li><li data-start=\"6003\" data-end=\"6040\"><p data-start=\"6005\" data-end=\"6040\">rarely worth the maintenance cost<\/p><\/li><\/ul><p data-start=\"6042\" data-end=\"6120\">It is generally not recommended unless you are building a very low-level host.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-f88ad5c e-flex e-con-boxed e-con e-parent\" data-id=\"f88ad5c\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-300fda1 elementor-widget elementor-widget-heading\" data-id=\"300fda1\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Is This an Editor Problem Only?<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-03436ea elementor-widget elementor-widget-text-editor\" data-id=\"03436ea\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"6162\" data-end=\"6200\">In most standard configurations \u2014 yes.<\/p><p data-start=\"6202\" data-end=\"6282\">The Stall Detector is compiled only when conditions like the following are true:<\/p><ul data-start=\"6284\" data-end=\"6352\"><li data-start=\"6284\" data-end=\"6299\"><p data-start=\"6286\" data-end=\"6299\"><code data-start=\"6286\" data-end=\"6299\">WITH_EDITOR<\/code><\/p><\/li><li data-start=\"6300\" data-end=\"6325\"><p data-start=\"6302\" data-end=\"6325\">not <code data-start=\"6306\" data-end=\"6325\">UE_BUILD_SHIPPING<\/code><\/p><\/li><li data-start=\"6326\" data-end=\"6352\"><p data-start=\"6328\" data-end=\"6352\">counters tracing enabled<\/p><\/li><\/ul><p data-start=\"6354\" data-end=\"6411\">In shipping builds, the detector is typically not active.<\/p><p data-start=\"6413\" data-end=\"6493\">So this behavior primarily affects <strong data-start=\"6448\" data-end=\"6477\">development and debugging<\/strong>, not end users.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-d75d053 e-flex e-con-boxed e-con e-parent\" data-id=\"d75d053\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-e029dc7 elementor-widget elementor-widget-heading\" data-id=\"e029dc7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Final Perspective<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1e4b7e5 elementor-widget elementor-widget-text-editor\" data-id=\"1e4b7e5\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"6892\" data-end=\"7047\">Embedding external native UI into a large engine inevitably creates moments where the engine\u2019s assumptions about thread behavior do not align with reality.<\/p><p data-start=\"7049\" data-end=\"7115\">The Stall Detector is doing its job \u2014 detecting something unusual.<\/p><p data-start=\"7117\" data-end=\"7188\">It simply cannot know that the thread is busy inside another framework.<\/p><p data-start=\"7190\" data-end=\"7266\">Understanding this distinction prevents countless hours of chasing non-bugs.<\/p><p data-start=\"7268\" data-end=\"7418\" data-is-last-node=\"\" data-is-only-node=\"\">Once properly configured, these interruptions disappear, and your integration can be evaluated based on real stability rather than debugger artifacts.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"featured_media":0,"template":"","asx-lms-tutorial-categories":[45,58],"asx-lms-tutorial-tags":[46,121],"class_list":["post-12642","asx-lms-tutorial-cpt","type-asx-lms-tutorial-cpt","status-publish","hentry","asx-lms-tutorial-categories-unreal-engine","asx-lms-tutorial-categories-unreal-c-api","asx-lms-tutorial-tags-cpp","asx-lms-tutorial-tags-debugging","entry"],"acf":[],"_links":{"self":[{"href":"https:\/\/store.algosyntax.com\/asx-rest\/wp\/v2\/asx-lms-tutorial-cpt\/12642","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/store.algosyntax.com\/asx-rest\/wp\/v2\/asx-lms-tutorial-cpt"}],"about":[{"href":"https:\/\/store.algosyntax.com\/asx-rest\/wp\/v2\/types\/asx-lms-tutorial-cpt"}],"version-history":[{"count":2,"href":"https:\/\/store.algosyntax.com\/asx-rest\/wp\/v2\/asx-lms-tutorial-cpt\/12642\/revisions"}],"predecessor-version":[{"id":12692,"href":"https:\/\/store.algosyntax.com\/asx-rest\/wp\/v2\/asx-lms-tutorial-cpt\/12642\/revisions\/12692"}],"wp:attachment":[{"href":"https:\/\/store.algosyntax.com\/asx-rest\/wp\/v2\/media?parent=12642"}],"wp:term":[{"taxonomy":"asx-lms-tutorial-categories","embeddable":true,"href":"https:\/\/store.algosyntax.com\/asx-rest\/wp\/v2\/asx-lms-tutorial-categories?post=12642"},{"taxonomy":"asx-lms-tutorial-tags","embeddable":true,"href":"https:\/\/store.algosyntax.com\/asx-rest\/wp\/v2\/asx-lms-tutorial-tags?post=12642"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}