No frame connection found on end of member system.
Each member system must have a start and an end frame connection. The lifetimes of these frame connections are controlled by the member system; hence, you cannot eliminate an end frame connection unless you delete the member system. Therefore, a member system without a frame connection should not exist.
Before Version 5, member systems without frame connections were allowed. Therefore, a migrated model can result in this situation. For a non-migrated model, this situation is abnormal and should not occur.
Commands that select a frame connection are affected. Examples of these commands include placement of members at the end of a member, placement of an assembly connection on a member system, and placement of analysis boundary conditions.
What You Should Do
To re-establish the connectivity of a frame connection, you can complete a manual process, or run a custom database command.
Before fixing this problem, you must have write access to the permission group of the member system. Frame connections always exist beneath the permission group of the member system. A new frame connection can only be generated if you have access to the member.
Select the member system part.
On the ribbon, click the Start and End frame connection buttons to create new frame connections.
Run the Clean Database custom command.
Select the member system(s) in error, and click Clean Now. The software creates new unsupported frame connections.