Weird plugin crash..

One of my plugins, it seems, is causing a server to crash in the following way with NOTHING in console:
For the first 5 minutes - a few hours it's fine.
However, soon after that all of the commands stop working on the server. All of the mobs stop moving. EVERYTHING besides chat basically stops, sometimes including console input. A little after that the server just completely crashes. Is this only me or is this happening to other people, and does anyone have an idea how to fix it?

 

you will want to hand us some code, if you have no errors oO

This happens when the server freezes and then crashes. could be happening when pasting too many blocks, or anything recursive in general oO

 

slipcor http://pastebin.com/8XprGLym
that's the main class, that's run in a runnable at a minimum of 60 ticks per run. Even with 'old_version' set to false, it still crashes eventually, even though it does alot less than the old version.

I could really use help with figuring this out, because i want to get a fix out asap, but i don't have a clue as to what's causing it.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

The loop "while(spacefound == false)" can result in an infinite loop if it loops a column that doesn't have any space anywhere (i.e. is filled with blocks from sky to bedrock).

 

njol good point... Hm