Here's what you do.
Start a game with all add-ons If that doesn't work, reinstall blockland. If not, try this:
Disable all addons. Then, check off a group of addons (ex. Bricks) and start a game. If it doesn't crash, then exit the game and disable the group. Keep doing this until it crashes. Then go through the group by enabling one add-on per game. That way you'll find the bad-on!