Its mabey a overload of Add-ons. These include the ones are not enabled too.Maps,Weps,Tools,Ect.If I am right, go to your Blockland Folder then Add-ons and delete some .zip folders you do not need.
Nope, didn't work
As a test, Make a new folder on your desktop as a normal folder should be. Name it whatever you want.Now, move most of the .zip folders to the new folder you created. This will act as a backup if this does not work or you need to move more .zip folders. Now Execute Blockland (Start it up).