I have 3 issues and workarounds in 4.11.
The character no longer receives mouse movement when the show mouse cursor is active on PlayerController. Some games (RTS, wow-style 3rd person) require this because you need menu and character interaction. The fix for now is a pull request 2206 (yes, source only) or some naughty workarounds … More is discussed in Show mouse cursor disables mouse events - Programming & Scripting - Epic Developer Community Forums . I hope they make a patch as soon as possible.
Character blueprint has currupt networking replication. In my situation, I have class hierarchy Character -> A (in C++) -> B (Blueprints) -> C (Blueprints). Everything works ok until you try networked game, when an assertion happens. The replicated variables pool is outdated. Recompiling B solved the issue but you have to do it everytime you open the editor (a workaround for now). Maybe smarter people may have more insight in how to fix it permanently.
On Windows, Lightmass does not build with VS2015 update 2 due to error: lightmasscore\math\LMMathSSE.h(586): error C3861: ‘_mm_cvtpu8_ps’: identifier not found. The workaround is to compile with previous version of visual studio.
I hope this is helpful, if anyone has additional comments, feel free to elaborate. I have found this thread (and ) really helpfull in transition from 4.10 to 4.11!
I met the _mm_cvtpu8_ps issue, according to your clue here, I compared the “C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\xmmintrin.h” for update1 and update 2, found it’s because now this “_mm_cvtpu8_ps” intrinsic is wrapped under “#if defined(_M_IX86)” so x64 target would not see the definition, hence the compile error.