http://hastebin.com/edifisimiz.profile
Mek: 7.0.0.75, also tried latest (7.1.0.90).
MC 1.7.10
Forge 1199
Crashes server on boot.

That's a lot of mods you have there.

I honestly don't know how this could be occurring - at the moment, there is no check I could add that could fix it. How did the issue originate?

Liquid is either oil or fuel. Both from buildcraft.

I've no idea. The server has been working fine, then I rebooted it to reduce ram usage and poof, le crash. Mc editing the tank out fixes that error, but then gives this: http://pastebin.com/Cb53bCa1. Mod interaction issue maybe? As in the tank is flipping out over a liquid from another mod?

Is this still occurring in that world? If so, I'd be very grateful if you could pack up your world, mods, and config folders and put them on a file-sharing site so I could check it out firsthand. I still am having trouble comprehending how this could happen.

Apparently not. Reloaded everything and it now works... Yay modded MC. Sorry if I wasted any of your time. Loving the mod.

No problem :)