Date: 2022oct24 Product: Microsoft Visual Studio 2017 Keywords: msvc, porting Language: C/C++ Q. c:\program files (x86)\windows kits\8.1\include\um\objidlbase.h(6173): error C2061: syntax error: identifier '__RPC__out_xcount_part' A. This happened to me when porting an older project to MSVC2017. I fixed it by removing the path to an old DirectX include folder from the project's properties.