would need to see source of PFDDialogs.cpp, find the origin of Yield, it is definetly redefined somewhere to nothing
error C2589: ';': illegal token on right side of '::'
means compiler sees
FPlatformProcess:: ;
which may be an effect of
#define Yield
what can cause problem is known, your goal is look in source and find what caused it. normally it should be obvious if you use a normal IDE like Rider or VS/Resharper - just navigate will show macro