Can somebody help me with t mod loader?

Im trying to join a friend on T mod loader, but every time i try to join him with calamity mod (No music), and calamity mod music, it will make it past the loading like the: joining ( Friends Username ) and it will make it past that stuff, then it will show *Calamity mod music* and it takes awhile to load, then the yellow loading bar will stop at the M in music. If you wait awhile nothing happens, And theres even a cancel button, when you press that, it just deletes the mod? Does anybody else have the same problem? Does anybody know how to help please!?