If you are using a Cisco FirePower and you are unable to save an object here is a quick and easy fix.
When you try to save the new object the “Saving Object” operation takes longer than expected, it may stay on this for a long period of time. Normally this should only pop up for a few seconds at most.
Once the above times out you may get the following error “Another operation by another user prevented this operation. Please retry after sometime“
The quick and easy fix for this is to reboot the Cisco FirePower management center. Details on how to do this can be found here.