Member part not attached to member part generator.
A member system consists of one or more member parts. When the parts of a member system are missing, no graphic operation can occur on the member system.
This member system has a database integrity problem and must be removed.
What You Should Do
Allow the delivered custom command to remove this member system.
Ask your database administrator to back up the model.
Supply all information possible that might have led to this situation, and submit this information along with the backup to Hexagon PPM Support.
Using the Clean Database custom command, remove this member system.