I was wondering if this was ever actually resolved. I have all the relevant DLC and the correct data path but after several attempts I've never been able to get the editor working, I always get "glasses has stopped working" when trying to enter the sandbox or any other level. Deleting my test level and creating a new one doesn't work.
It's quite frustrating; although I'm just a tinkerer rather than someone who uploads mods, it would be nice to be able to mod the game but so far it's not happening...