I can only guess that ms recently did some massive changes to msvc 2013 so be carefull when updating it, as they have stated that the old multibyte support libraries will be removed completely. well i got it to compile but it crashes when loading any mission, btw do i need a new shader for the changes you made ? also i had to make some workarounds in draw_arb2.cpp as newstage is not defined anywhere the compiler refused to compile it. i fixed that by looking at the code in draw_common.cpp to see how newstage was defined, which btw left some questions as it seems to disable certain parts, like ambient lighting. msvc2013 also needs recompiled versions of boost to be able to build darkmod, but if what you say is true i suspect greebo simply uses the 2010 toolset from the msvc 2013 interface.