The server just went down again, and I think I know the problem why it happened and why it happened yesterday too.
Around 12000, 2000 there are a bunch of chunk errors. Yesterday the server went down when me and some other guy went to check them out. But, I had no idea that's why it went down. So just now, I jumped into a chunk error that was filled with water and the server went down.
I'm pretty sure this is why the server went down, unless its just a huge coincidence. I think its time for a new map anyway..