Trying to edit a Model Type gets a RSOD

(Bug, To be Fixed , Priority: Medium, Test Status: No automated tests yet , Reported By Bad Link: Thing 3y284oe not found, )
Summary: Not sure whether editing other Types has the same result, but it repros when trying to Edit a Model Type.
Not actually sure what should happen here. Editing a Type certainly isn't legal yet. This only comes up if you click on the Type of a Model Property; arguably, that should go to the actual Model instead of the Type, since that is almost always what you actually want...