Err my tutorial might help:
Right click on the Blockland short-cut then this will pop up:
Click "Properties"
Then this should come up:
Then add " -mod editor" Without the " at the ending of the Target. should look like this:
Then click "Apply" then you're done.
To use: Just go in-game then click "F10" or "F11" F11 is the mission editor and F10 is a gui Editor/Creator.
I hope this helps %100.
Here it is WITHOUT photos