FSlateApplication not found in UE 4.3

Just upgraded the Unreal Project and the C++ project using the automated upgrade tool but I can’t compile at all. Lots of errors but all mainly seem to be centered around FSlateApplication

error C3083: 'FSlateApplication': the symbol to the left of a '::' must be a type

Is this a bug that slipped in or is there some new header or module we need to include in 4.3 vs 4.2 projects?

Edit: I also have Slate and SlateCore in my Build.cs:

PrivateDependencyModuleNames.AddRange(new string[] { "Slate", "SlateCore" });

Hi ,

One of the changes in 4.3 is that a number of includes were removed from Engine.h in order to improve compile times. Slate.h is one of the includes that was removed, and if you are using Slate you will need to add that include back in. Give that a try and please let us know if the errors continue to appear.

From the update notes:

Gameplay and Framework

  • Significant changes to Engine Headers
  • Engine.h has had lots of headers removed to reduce game compile times. We have tried to only remove classes that are unlikely to be used by a game project, but if you see compile errors, you may need to include additional headers.
  • Slate.h no longer included by Engine.h, so if you are using Slate, you will need to include yourself.

Ah, didn’t see that. I included “SlateApplication.h” as that seemed to be where the class was defined but that just produced a different set of errors. All good now. Thanks!