Installing this plugin on a test environment to play with it and try it on for size.
I've created a bunch of custom types and have gone in to try and give them cleaner permalinks. This seemed to work fine and I went through a few types and saw no problems, then I went to edit some content and as I save the updates I get sent to a Server Error page (500). I'm not able to save any edits, I've gone to the wp>settings>permalinks page to check on that and refresh the permalinks with no success. Now I'm trying to turn the CCTM urls field back to off and get the same response. I can't edit or add any new content of that type anymore. The others all seem fine still, but I'm not sure what could have happened. I even deleted the content type and recreated it only to get the same error.