I recently updated Visual Studio and i got an error while trying to compile Direct3D11 App based on Frank Luna's Book (Introduction to 3D Game Programmig with DirectX11) which DxTrace was used in it.

Error :

Severity    Code    Description    Project    File    Line
Error    LNK2019    unresolved external symbol __vsnwprintf referenced in function "long __stdcall StringVPrintfWorkerW(unsigned short *,unsigned int,unsigned int *,unsigned short const *,char *)" (?StringVPrintfWorkerW@@YGJPAGIPAIPBGPAD@Z)    DirectXApp    D:\Projects\DirectX\DirectXTest\DirectXAppTest\DirectXApp\dxerr.lib(dxerrw.obj)    1

I finally found out that when i compile it using Visual Studio 2013 compiler it works!

What is the main reason that i didn't compile using Visual Studio 2015 compiler ? and how can i make it work?

This link was helpful : Linker error compiling DX10 program in Visual Studio 2015

The function StringVPrintfWorkerW is trying to use the function called __vsnwprintf which your linker cant find at the moment. Tell the linker which .lib file that function is defined in and you will see that the compile will work again. https://msdn.microsoft.com/en-us/library/1kt27hek.aspx