Quick answer: Windows blocked or couldn’t load the Fab plugin’s DLL (UnrealEditor-Fab.dll), so the editor stops. To fix it:
- Open your project now: turn Fab off in your
.uproject(shown below). Your project and your Fab assets still work. Only the Fab window in the editor goes away. - Did Windows show a “Bad Image” message or error 0xc0e90002 first? Then Smart App Control is blocking the DLL. See Cause 1.
- Otherwise: remove the Fab plugin in the Epic Games Launcher, then install it again for your exact engine version.
- Delete any old Fab folder inside your project’s
Pluginsfolder.
The full error
Plugin 'Fab' failed to load because module 'Fab' could not be loaded.
There may be an operating system error or the module may not be properly set up.
“Could not be loaded” means Unreal found Fab’s DLL, but Windows refused to load it. That’s different from “could not be found”, which means the file is missing (see module could not be found).
Step 1: Open your project without Fab
Close Unreal. Open your .uproject file in Notepad and add Fab to the Plugins list with Enabled set to false. If there’s already a Plugins list, add only the { ... } entry to it.
"Plugins": [
{
"Name": "Fab",
"Enabled": false
}
]
Save and open the project. You can turn Fab back on later in Edit > Plugins once it’s fixed.
Step 2: Find the cause
| What you see | Likely cause | Go to |
|---|---|---|
| A Windows “Bad Image” message, or error 0xc0e90002 | Smart App Control is blocking the DLL | Cause 1 |
| The error started after an engine or Fab update | Broken or mismatched Fab install | Cause 2 |
A Fab folder inside YourProject/Plugins | Old copy loading instead of the engine’s | Cause 3 |
| A source-built or custom engine | Launcher Fab doesn’t match your engine | Cause 4 |
Not sure? Open the newest .log file in YourProject/Saved/Logs and search for Fab. A “Missing import” line names a DLL that Fab needs and can’t find.
Cause 1: Smart App Control is blocking Fab
On Windows 11 with Smart App Control turned on, UE 5.8.4 users report Windows blocking UnrealEditor-Fab.dll on every launch. Reinstalling Fab and verifying the engine didn’t help them.
To confirm it, open Event Viewer and go to Applications and Services Logs > Microsoft > Windows > CodeIntegrity > Operational. Look for event 3077 that names UnrealEditor-Fab.dll.
You have two options:
- Keep Fab off (Step 1) until Epic ships a Fab build that passes the check. This is the safe choice.
- Turn Smart App Control off in Windows Security > App & browser control > Smart App Control settings. This lowers your PC’s protection against unknown apps, not just for Unreal. On Windows 11 updated since April 2026 you can turn it back on later. On older builds, turning it back on needs a Windows reset.
Other antivirus tools can block or quarantine the same DLL. Check your antivirus history for UnrealEditor-Fab.dll before reinstalling anything.
Cause 2: A broken or mismatched Fab install
The Fab plugin is built for one engine version. A half-finished update, or a Fab folder copied from another engine version, leaves a DLL that won’t load.
- In the Epic Games Launcher, go to Unreal Engine > Library.
- Under your engine version, open Installed Plugins and Remove Fab.
- Click the arrow next to your engine version and choose Verify.
- Find Fab in the Fab Library section and choose Install to Engine for your exact version.
Fab lives in Engine/Plugins/Fab on recent versions (older installs use Engine/Plugins/Marketplace/Fab). Never copy that folder between engine versions.
Cause 3: An old Fab copy in your project
If YourProject/Plugins/Fab exists, Unreal may load that old copy instead of the engine’s. Close Unreal, delete that folder, and open the project again.
Cause 4: Source-built or custom engines
The Launcher’s Fab plugin is built for Launcher engines. On a source-built engine or a custom one (for example Aximmetry’s), keep Fab disabled and get your assets from fab.com and the Launcher’s Fab Library instead.
If the failing module is from one of our plugins, download the build for your exact engine version, or send us your log.
FAQ
Will disabling Fab break my assets? No. Assets you already added are normal project files. Fab is only the in-editor store window.
Does deleting Binaries and Intermediate help? No. Fab is an engine plugin, so those project folders don’t contain it.
Why does this happen in every project? Fab is installed into the engine and turned on by default, so every project tries to load it.