Basically what I'm trying to do is create an island in a new worldspace. I can open the heightmap editor and create a landmass just fine, and I can save it as well, but as soon as I exit the heightmap editor the CK crashes. I assume that I can save the changes in the plugin itself as well, then exit the CK and start it up again, but that's pretty tedious.

Anyone know of a cause or fix for this?

I don't think you can save because I think CK doesn't let you save if anything is opened. Might be wrong on this though.

Okay, but the same thing happens even if I don't save the heightmapping work.