VS 2015升级到Update 3后，Unreal编译时会出现4599错误，原因是VS 2015 RC3中有以下更新:
“When using PCH files, mismatched -I include directories to the compiler between -Yc and -Yu compilations will now produce a new warning. C4599”
解决方案：
在工程中找到WindowsPlatformCompilerSetup.h，在warning列表中把4599删除，这样就可以避免4599的错误提示并成功编译了。
参考：
https://answers.unrealengine.com/questions/435600/build-failed-with-vs-2015-update-3.html