Quick answer: only upgrade mid-project if the new version gives you something you need: a bug fix, a feature, or a platform requirement. If you do upgrade:
- Back up or commit your project first.
- Check your plugins support the new version.
- Open the project in the new engine and choose Open a Copy (the default). Never pick Convert in-place.
- Test the copy properly before you switch over for good.
Upgrading is one-way
Once a project is opened and saved in a newer engine version, you can’t open it in the older version again. That’s why the copy matters. If the upgrade goes wrong, your original project is still there, untouched.
When it’s worth upgrading
- A bug that blocks you is fixed in the new version.
- You need a new feature that would take you longer to build yourself.
- A platform or store requires a newer version (consoles, mobile SDKs).
- You’re early in the project and have little to lose.
When to wait
- You’re close to release. Ship on the version you’ve tested.
- A plugin you rely on doesn’t support the new version yet.
- The new version came out days ago. Many teams wait for the first hotfix (the .1 or .2 release) so others find the early bugs first.
- You just want to be “on the latest”. That alone isn’t a reason.
How to upgrade safely
Step 1: Save a restore point
Commit everything to version control, or copy the whole project folder somewhere safe.
Step 2: Check your plugins
Look at each plugin’s store page or Fab listing for the new engine version.
- Marketplace and Fab plugins need a build for the new version. Install it in the new engine through the launcher.
- Plugins inside your project’s Plugins folder with source code will be rebuilt. Some may need small code fixes first.
Step 3: Open a Copy
Open the .uproject with the new engine. In the conversion dialog, click Open a Copy. Unreal copies the project, upgrades the copy and opens it.
Epic warns that Convert in-place (under More Options) can corrupt or lose data if the conversion fails. Avoid it.
Step 4: Fix and test
- If you see “The following modules are missing or built with a different engine version”, click Yes to rebuild. If it fails, open the project in your IDE and build there to see the real error.
- Play through your main levels, check your UI, and package a build. Some problems only show up in a packaged game.
Common upgrade problems
| Problem | Usual fix |
|---|---|
| “Modules are missing or built with a different engine version” | Rebuild the project; see our guide below |
| A plugin fails to load | Install the plugin’s version for the new engine, or wait for an update |
| C++ compile errors after the upgrade | Engine functions were renamed or deprecated; check the release notes |
| Materials or lighting look different | Check the release notes for rendering changes and project settings |
FAQ
Can I go back to the old version after upgrading?
Not with the upgraded project. Use the original copy or your version control history.
Do I have to upgrade at all?
No. Many games ship on the version they started on. Upgrade when it solves a real problem.
Can I skip versions, for example 5.5 straight to 5.7?
Yes, you can open a project in a version several releases newer. Bigger jumps mean more changes to fix, so read the release notes of every version in between.
Related articles
Using our plugins? Each Algosyntax plugin lists the engine versions it supports on its product page. If you’re planning an upgrade and need a version you don’t see, contact us before you switch.