If you have decommissioned a vCenter without unregistering it with the Prism and now are unable to complete the task, there may be a solution.

For AOS 5.5.x provided the symptoms match an upgrade may be required to resolve the issue. If you see all of the following, upgrade to AOS to 5.5.6, 5.8.2, 5.9 or later.

• An attempt to unregister a vCenter instance that does not exist anymore from Prism using vCenter Registration page creates a task that fails at 100% progress.
• Using the "ncli managementserver unregister" command produces the same outcome.
• Uhura logs (home/nutanix/data/logs/uhura.out) show vCenter is not reachable and is not able to delete the connection object.

Nothing is fully predictable - we understand that. Some things still can be planned. We encourage you to plan the maintenance, especially when it comes to decommissioning of the components. It is generally more difficult to solve the problem where a component no longer exists then while it was still available.

For more details on the Uhura log output observed with the issue see KB-5267 Scenario: Forcefully remove stale vCenter registration