Fix: Unreal Blueprint Event Graph Pin Mismatch After C++ Refactor

Renamed C++ function parameter from int32 to FName. All calling blueprints show as broken.

Compile all blueprints

UE4Editor.exe -run=CompileAllBlueprints -ProjectOnly

Surfaces every broken BP. Lets you fix systematically rather than discovering at PIE.

Or use Refactor > Rename

For local renames, Rider/VS refactor handles BP pins. Manual rename loses the pin link.

Mark BlueprintCallable carefully

If a function is BP-callable, signature changes are breaking. Treat like a public API.

“Blueprint pins are serialized references. C++ refactors are migrations.”

Reserve BlueprintCallable for stable APIs. Internal C++ refactors don't break BP if the function isn't exposed.

Related reading

• Fix: Unreal Blueprint Async Result Pin Blank
• Fix: Unreal Blueprint Set Actor Scale Physics Mismatch
• Fix: Unreal Anim Graph Leaks Pose Cache After Blueprint Recompile
• Fix: Unreal Blueprint Timer By Event Not Firing On Server