Symantec Management Platform.
Notification Server Events (NSE) error occurs frequently, although there is no AD Import or event queues being moved.
Attempt to save messaging resource f18ffd66-1361-46e9-8aaf-f6ff8a2bb747 has been blocked by the Host Resource Blacklist.
ITMS 8.0 HF6
The GUIDs of machines appearing in the error, are added to 'AgentBlacklist' table. These machines are there in 'RM_ResourceVirtual_Machine' or 'RM_ResourceComputer' table but missing from 'vComputer'. Deleting the GUIDs only from 'AgentBlacklist' table does not work, as it gets added again when inventory is sent from client machine.
Remove entry of this GUID from 'RM_ResourceVirtual_Machine' or 'RM_ResourceComputer' table first, then from 'AgentBlacklist' table and send basic inventory.
Note: Please take full SQL backup before making any changes to database (Symantec_CMDB).