What It Means & How to Fix It in UE5
🧠 Why You’re Seeing This Error
This error is a global warning, meaning one or more Blueprints in your project failed to compile, and something in your current Blueprint depends on them.
In UE5, this happens when:
- Another Blueprint you’re referencing is broken
- A Blueprint you inherit from, cast to, or use in a variable has a compilation error
- You’re trying to run or package the project, and Unreal detects invalid Blueprints
- You have circular dependencies or cross-referenced errors
💥 Example Error Message
One or more Blueprints has an unresolved compiler error, are you sure you want to continue?
You’ll usually see this when compiling, saving, or closing a Blueprint.
🛠️ Common Blueprint Scenario
Blueprint A → Uses or inherits from → Blueprint B
Blueprint B → Has a broken node or deleted variable
→ You open Blueprint A → Error appears, even if Blueprint A looks fine
✅ How to Fix It in UE5 – Step-by-Step
✔️ 1. Open the Message Log or Compiler Results
Window → Developer Tools → Message Log
OR
Compile → Check Compiler Results panel
This shows exactly which Blueprint(s) are causing the error.
✔️ 2. Open and Compile Every Referenced Blueprint
- Open each Blueprint listed in the message log
- Click Compile
- Fix any broken nodes or variables
Check especially:
- Blueprints used as variables or parents
- Actor Components
- Widget Blueprints
- Interfaces
✔️ 3. Recompile Your Current Blueprint After Fixing Others
Once the dependent Blueprints are fixed:
- Go back to your original Blueprint
- Click Compile again
The error should now disappear.
✔️ 4. Run “Fix Up Redirectors” (Optional)
Sometimes the Blueprint still references outdated or renamed assets.
Right-click on /Content
→ Fix Up Redirectors in Folder
✅ Summary: How to Fix “One or More Blueprints Has an Unresolved Compiler Error” in UE5
| Cause | Fix |
|---|---|
| Referenced Blueprint has errors | Open and fix the actual Blueprint that’s broken |
| Inherited class is broken | Compile the parent Blueprint or class |
| Cross-reference or dependency issue | Compile Blueprints in correct order |
| Leftover redirectors or assets | Run Fix Up Redirectors to clean up asset links |
