kinda offtopic, I'm programming C# in VS13. Will my codes and the coding style be same if i update to VS2015?Either revert these changes, or use VS 2015.
You are using MPIR libs for MSVC 2013 with MSVC 2015.
Either get the MPIR libs for 2015 or compile them yourself. You can find all the info you need on MPIR's site.