Server crashing, with following error NOONE KNOWS WHAT IT IS! DO YOU?

Logblock has been giving me the same error since before I started having the crashes, but I have since determined that without any plugins installed my server has still yet to crash.

Edit: Still no crash with no plugins, so I've added half my plugins back in and started it up.
I've now put two test servers online, 1 with the first half of the plugins enabled, 1 with the second half of the plugins enabled. Hopefully within a few hours I will have half of the plugins eliminated