Crash-Report: http://pastebin.com/y2GAiUj0
Forge version: 1.7.10-1614.46

Whenever someone clicks a MCA villager it instantly crashes the server.

This seems to be caused by a mod by SpitefulFox, not MCA. Which mods are you using apart from MCA and RadixCore?

The cause is most likely Forbidden Magic, SpitefulFox's Tinker's Construct 4 plugin.

Please notify the author of your mod pack about this.

All mods on this modpack: https://www.atlauncher.com/pack/CrundeeCraft

Yup, not MCA.