Yes please attempt the rename first. From the gui image I'm suspecting that you are using R80x so you might not want to fiddle with the guiDBedit without doing a full mds_backup (I know you've probably already did this but... yah)
Secondly which object are you trying to remove? The global level one or the CMA/Domain level one?
Are you able to detach the global? If so are you able to rename the CMA level one, save and then see if you are able to delete that local object?
Are there any errors when you "install database" can you provide the output of that?
If you are still not able to, look at sk115557 R80.x Security Management server main processes debugging to see how to enable debugs for the CPM and see why that CMA is being cranky.
If possible provide the debug outputs. Best of luck.