I've been trying to remove an old, decommissioned vCenter from Networker 9.2.1.5 but keep getting:

Error - This hypervisor is still referenced by task (IP of vCenter)

From what I can tell, there are no Groups or Policies left pointing to that vCenter.

I've been Googling for hours now and can't seem to find any threads or articles referencing how to delete the task that is associated with this vCenter. Can somebody point me in the right direction?