Oh I've gotten this message soo many times...Make sure you have the right file path for every mesh (I'd take a look, but I'm on a mac right now). Remember that you need the file type at the end too (EX: meshbank\user\mesh.x)
Basically, if it says mesh number illegal, it means there's a problem with something that has to do with the model file in the .fps
If that doesnt work, check how many partmodes you have. If the last part is 10, then you need to include the 10 AT THE BEGiNNING, where it says Partmax =
Also include that same number where it says lastmeshmax =
A picture says a thousand words.
--H.K.--
http://www.fpscx10-online.com/