http://pastebin.com/yTzf3Xxc

I have no idea what the exact item is that's causing the issue but it looks like any redstone could cause it from the crash.

Can you reproduce this in a fresh world?

I could not reproduce it in singleplayer. I don't know the exact specifics that's triggering it.
The person is using an advanced redstone interface with filters and then switches them out as needed but the crash is happening when people are switching dimensions on the server.

Thanks! It does seem to be quite random as it works fine then randomly on someone switching DIM's it will crash.

kk, will try to just make it a bit more "secure" then