Thanks Jonathan for your responses here and on the Protege mailing list. It's interesting that you don't observe the same behavior when dragging a class into the instances field. I have repeated this multiple times by creating test classes, and each time the classes have dissapeared as soon as I dro...

Hi, After attempting to generate an XML export of a class using the XML Tab in Protege, the class is now missing from the Class Browser area. We queried the database and were able to see the instances of that class, even though they are not visible anywhere in Protege. I took the following steps to ...