Hey,
Trying to compile my project in 4.20 (using vs2017) gives me the following error:
2>F:/UE4_Install/UE_4.20/Engine/Plugins/Marketplace/DungeonArchitect/Source/DungeonArchitectRuntime/Public/Builders/SnapMap/Connection/SnapMapConnectionActor.h(22) : LogCompile: Error: An explicit Category specifier is required for any property exposed to the editor or Blueprints in an Engine module.
Edit: looked at the code, my guess is you need to add a category to this line:
UPROPERTY(BlueprintReadOnly, Transient)
AActor* SpawnedInstance;
I tried this and it worked:
UPROPERTY(BlueprintReadOnly, Transient, Category = DATest)
AActor* SpawnedInstance;
Regards