Unable to unregister from Fortimanger

[Seferian1]

Hai all,

After not using Fortimanger enough to justify the costs I've taken in out of the Fabric. So far so good. 

All FG's accepted this as it came down from the Fabric. However one failover FG now has a sync problem. After investigating this I've found that it still thinks it has central management. While the Active FG does not. 

In order to clean this up I tried to unset the central-management on the failover FG. This is where I run into a bug/issue. I can't seem to unregister the FM. I'm getting the following error:

Please unregister-device from FortiManager first.
object set operator error, -582 discard the setting
Command fail. Return code -582

Googling this gives me the advice to set the fmg ip to 0.0.0.0. https://community.fortinet.com/t5/FortiGate/Technical-Tip-Unable-to-delete-the-FortiGates-central-ma...After doing so i should be able to set the type to none. This however does not work. I'm getting the same error.

Does anyone have a solution to this? It's not the end of the world but I'd rather have the FG's in sync.

Thanks!

[AlexC-FTNT]

If everything else is synchronized, then change the roles of the FortiGates (promote Backup to Active), and then try to change the IP again (from GUI, not CLI).