Use of a '$' character in Stereotype names corrupts the saved MDZIP file
While it is not recommended by the tool vendor, you can get away with using a '$' in the name of some (only) Element types, but NOT for Stereotype names.
If you do a accidentally break an MDZIP file using bad characters in the model, you can usually (sometimes) fix them relatively easily by using the unzip/edit/rezip procedure described here: