Member system axis end port (at end) is related to more than one axis joint.
The end of a member system can be related to only one axis joint. This axis joint defines the end location of the member system's logical axis.
Any manipulation of the member system will fail.
What You Should Do
Remove the offending 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.
Open the model.
Select the offending member part, and delete it.