some of our printers were classified as workstations as during a recent scan.  when I try to modify the product type I get a HTTP status 500- box pop up with a bunch of information on it.  I have uploaded a snipet of the error message.  The product is already defined in the products section and when I select it and hit apply this is what I get.

This happens for ANY product I try to update or change.

Thanks for your help.