Is it a runtime?
Take these out of your blockland folder to see if it fixes the problem (don't delete, just put them on your desktop or something):+ System_BlocklandEssentials+ Support_Rendermen+ System_ReturnToBlocklandThese are the add-ons I'm assuming are crashing your client, please takes these out and see if it's confirmed.
The only things I want from BlocklandEssentials are the eventing buttons and the better server list.
If you have the themes addon, Delete it, Cause when i had it, the game crashed every time i used the printer on a print brick, So yeah, i hope this helps anyone :P