While looking at a problem described in a thread at AUGI I stumbled upon a very subtle awkward crash which I've submitted to Autodesk naturally.
To get in trouble you need to be using the Model Text feature and attempting to create a parameter to manage the height of the text.
The steps are:
I started in the Generic Model.rft Family Template
Add Model Text
Select the Model Text
Click Properties button to see the Instance Properties
Click Edit/New to see the Type Properties
Click Associate Family Parameter button (little gray square button, see image)
Click Add Parameter where the only available option is (None)(see image)
Nice friendly message appears (see image)
Work-around Note: if a valid parameter exists, and appears in the dialog, already you can select it instead and Revit won't crash. Revit only crashes if there is no parameter already and you need to click Add Parameter to create one on the fly.
Fwiw, it doesn't crash the upcoming release...