If you're using any sort of .dll file or patch_mp.ff then it is probably that. You're going to need to either fix the scripting or use a new .dll file if you're on TU7 or a patch if you're on TU6 or below.

i had this problem to. The way i fixed it was by re-installing it to my jtag and running it from he default.xex (same as default_mp.xex just from main menu). but there are many problems it might be that ur default_mp.xex is trying to run a different file name to the .dll for example i have a .dll called ShArk.dll and i have to have a specific default_mp.xex to run it called ShArk_default.xex so in short u need the right .xex for the right .dll if u cant find one ill post a link to a working on for u.

(sorry if its long)