I have the Ultimate Pack 1.0.1 on my server and I'm trying to add a couple of mods (Ars Magica, Doggy Talents, Hats, and Tinkers Construct) all I did was add the mods to the servers 'mod' folder which is probably the wrong thing to do. The server starts up fine, no errors or anything but when I try to connect with the same mods I get this error. It seems it only has problems with Ars Magica and Tinkers Construct.
http://pastebin.com/UUeFvvcu
http://pastebin.com/UUeFvvcu