Error while building QGC source code in release mode in windows

i am getting this two error while i try to get the executable file for my modified QGC application

error1-C:\qgroundcontrol\src\MissionManager\ error: C2220: warning treated as error - no ‘executable’ file generated

error 2-:-1: error: LNK1257: code generation failed

what should i do?
please reply asap