What happened to the server?

Earlier tonight I finished my dungeon including over 100 mob spawn points which are a pain to set up even 1, when the server went down. So I left to do somthing else for a few hours. When I came back, everything I had done today had been lost. Was the server reverted? or is it just a bug, because I was lagging really bad earlier.

Let me do the mob spawning work , you need to //save it and //reload it so many times for it to actually work

Alright, I will put a sign with each mob and where I want it, you should be able to do /warp dungeon_jj or jj_dungeon to get to me.

Update: I put redstone torches where I want the mobs spawned, There should be a sign near every torch letting you know what mob(s) I want spawned there.
Also, the prizes, how do I set up the chests to work properly?