Uhm, there's a console.log file in the Blockland folder. It's rewritten every time you run the game, and gives information on what's loading, connections made, etc.
From my experience w/crashes, it will crash just before it writes to the log, so the add-on you're looking for may be whatever is supposed to load after the last thing to written in the log.
Usually the add-ons load in reverse alphabetical order.
If you want further help identifying the bad addon, you could upload the /console.log and, there's another file to tell us what is enabled. I think it's like: /config/server/ADD_ON_LIST.cs or something like that.
