I’m getting this error when I try to package my project:
“PackagingResults: Error: An explicit Category specifier is required for Blueprint accessible functions in an Engine module.”
I can’t find much online about it - Anyone have any idea what could be causing this?
Hi @Milo_911!
Usually that error code is paired with more errors. Would you mind sharing your full error log?
In the meantime, here is another forum thread with the same error that can possibly point you in the direction of what you are looking for!
Any additional information you can provide will be a big help in solving your problem!
Thats weird and a little worrying!
The full log is just this:
PackagingResults: Error: An explicit Category specifier is required for Blueprint accessible functions in an Engine module.
PackagingResults: Error: An explicit Category specifier is required for Blueprint accessible functions in an Engine module.
PackagingResults: Error: An explicit Category specifier is required for Blueprint accessible functions in an Engine module.
PackagingResults: Error: An explicit Category specifier is required for Blueprint accessible functions in an Engine module.
PackagingResults: Error: Unknown Error
Hey @Milo_911!
That is very odd, usually there would be something like
UATHelper: Packaging (Windows (64-bit)): D:/Program Files (x86)/UE_4.21/Engine/Plugins/Marketplace/MultiPacker/Source/MultiPackerRuntime/Public/TileUtils/TilePointer.h(18) : LogCompile: Error: An explicit Category specifier is required for any property exposed to the editor or Blueprints in an Engine module
for example, that would specify where that error is.
Could you attempt to package again and see if you get a longer log? Also, as a relevant side not, do you have any older plugins in your project?
Just packaged it again, it immediately fails with the same exact error from above 
I have about a dozen plugins enabled, but all of them meet my current engine version.
Update! After restarting the engine and packing a few more times, I managed to get that UTAHelper message along with the error -
UATHelper: Packaging (Windows (64-bit)): C:/Program Files/Epic Games/UE_4.26/Engine/Plugins/Marketplace/ProceduralAnimationFramework/Source/ProceduralAnimationFramework/Public/ProceduralMovementComponent.h(75) : LogCompile: Error: An explicit Category specifier is required for Blueprint accessible functions in an Engine module.
UATHelper: Packaging (Windows (64-bit)): C:/Program Files/Epic Games/UE_4.26/Engine/Plugins/Marketplace/ProceduralAnimationFramework/Source/ProceduralAnimationFramework/Public/ProceduralMovementComponent.h(77) : LogCompile: Error: An explicit Category specifier is required for Blueprint accessible functions in an Engine module.
UATHelper: Packaging (Windows (64-bit)): C:/Program Files/Epic Games/UE_4.26/Engine/Plugins/Marketplace/ProceduralAnimationFramework/Source/ProceduralAnimationFramework/Public/ProceduralMovementComponent.h(79) : LogCompile: Error: An explicit Category specifier is required for Blueprint accessible functions in an Engine module.
UATHelper: Packaging (Windows (64-bit)): C:/Program Files/Epic Games/UE_4.26/Engine/Plugins/Marketplace/ProceduralAnimationFramework/Source/ProceduralAnimationFramework/Public/ProceduralMovementComponent.h(81) : LogCompile: Error: An explicit Category specifier is required for Blueprint accessible functions in an Engine module.
PackagingResults: Error: An explicit Category specifier is required for Blueprint accessible functions in an Engine module.
PackagingResults: Error: An explicit Category specifier is required for Blueprint accessible functions in an Engine module.
PackagingResults: Error: An explicit Category specifier is required for Blueprint accessible functions in an Engine module.
PackagingResults: Error: An explicit Category specifier is required for Blueprint accessible functions in an Engine module.
Looks like your problem originates from Procedural Animator Framework, as that plugin seems to be 4.26 only, and since you are working in 4.27 it is incompatible with your current project. I would check the solution in the prior linked thread to see if that acts as a fix for you.
I hope this helps correct your problem at hand.
You need to add a
Category=“Something”
to every UPROPERTY or UFUNCTION that is exposed to Blueprints, the error shows you which lines are missing that specifier, edit the file ProceduralAnimationFramework/Source/ProceduralAnimationFramework/Public/ProceduralMovementComponent.h at lines 75, 77, 79 and 81