Full Message: Fatal Error C1047: The object or library file 'file' was created with an older compiler than other objects; rebuild old objects and libraries
C1047 is caused when object files or libraries built with /LTCG are linked together, but where those object files or libraries are built with different versions of the Visual C++ toolset.
This can happen if you begin using a new version of the compiler but do not do a clean rebuild of existing object files or libraries.