looking at the code, it doesn't make sense, a compiler is valid if it's C compiler program can be found [m_Programs.C] [note : C++ compiler can always do C too]., either in the MasterPath or in the extra Paths, the fact that "additional paths " is empty should not make it invalid, and so says the code. :shock:
Are you really sure you didn't have another problem ??
What did you specify as MasterPath (could be maybe in your masterpath you already specified the bin subdir, you shoulnd't , CB itself will append the bin subdir).
And for additional paths it doesn' t add anything, so when this might be set to the MasterPath (ending with the bin) dir, this could explain that in your case with your change it now works. But as far as I can see, it is correct, so no need for code changes.