How can i do ,when I use the"IPlatformFilePak.h"

In My .cpp
when i use this"#include “PakFile/Public/IPlatformFilePak.h” there are so many errors,Please help me,thanks!

E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(18) : error C2143: ???: ???;??(???)
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(18) : error C4430: ??? - ??? int???: C++ ??? int
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(19) : error C2144: ???:??FThreadSafeStaticStat???;??
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(19) : error C4430: ??? - ??? int???: C++ ??? int
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(21) : error C2144: ???:??FThreadSafeStaticStat???;??
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(21) : error C4430: ??? - ??? int???: C++ ??? int
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(36) : error C4430: ??? - ??? int???: C++ ??? int
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(36) : error C2086: ??int PAKFILE_API??: ???
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(21): note: ???PAKFILE_API???
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(36) : error C2146: ???: ???;??(???TPakChunkHash???)
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(302) : error C2079: ??FPakFile??? class??PAKFILE_API??
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(302) : error C2143: ???: ???;??(???:???)
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(302) : error C2059: ???:??:??
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(302) : error C2059: ???:???
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(303) : error C2143: ???: ???;??(???{???)
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(303) : error C2447: ??{??: ???(???)
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(919) : error C2079: ??FPakNoEncryption??? class??PAKFILE_API??
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(920) : error C2059: ???:??public??
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(922) : error C2332: ??enum??: ???
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(922) : error C2143: ???: ???;??(???{???)
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(922) : error C2447: ??{??: ???(???)
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(935) : error C2059: ???:??}??
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(935) : error C2143: ???: ???;??(???}???)
E:\UE_4.20\Engine\Source\Runtime\PakFile/Public/IPlatformFilePak.h(939) : error C2989: ??PAKFILE_API??: ?? ??? ??? ???