Like SRB2 itself, EXE modifications check the resource wads to make sure that they are correct for the version you are using - SRB2CB is an EXE mod that was based on a prior version of SRB2, and you must use it with that version.
Which is to say, make a separate installation of SRB2 2.0.7 (find it in the archived versions section of srb2.org), and try using SRB2CB with that. I don't know which version SSBC or the other one used, but they're probably still 2.0. Otherwise, try 1.09.4.