Server Crashing

Hello there,

I have this problem with my server were it keeps crashing. I know what is causing it which is the ars magica 2 mod but originally it was working and now it isn't. I don't know what to do, is it clashing with another mod? I ran it in single player with all the other mods I have currently but it was fine. Ars Magica was one of the first mods I ran on my server with other mods and now it's making it were the server wont start. (The server begins to start but before you can even log on it stops). Could someone please help? If you need the log it is > Logs

This is the full log

The server didnt even stay up for a second, it just got to the point were it was gonna open and it didnt instead it stopped. I saw it stop and went to logs and hit the share button.