So after correcting some errors I can't nest a model any more. I have no idea what the heck is happening here.
After poking with a stick it appears that I CAN nest it if I create a new model and pull from those sources, it nests just fine then. Tried disabling design history with no luck too.
What the heck is happening here? This is the second model that I've had this happen on and it's not great.
