Remove correctly selected NSManagedObjects

Answer 1

If I understand your description of how everything is built up correctly, selectedObject in your NSPopupButton is bound to some value in your NSTableView.  My guess is that you are using dataSource methods to provide the table with data, and bindings to match the data in the popup with the table.

You should probably use an NSArrayController for the actual dataset, bind its content array to an NSMutablearray in your controller, and bind both the tableView and the NSPopupButton to the arrayController, instead of binding one control to the other.  The problem you describe does not seem to have very much to do with NSManagedObject, except for seeing a default implementation of -description in this situation, but moreso with using bindings in an unconventional way.

Answer 2

I have it!
I just unbinded the selected object of the NSPopUpButton and binded it again. It performs this action only when the selected object was removed from list. ;)