UIM Portal was not opening, and it displayed an error:
'CM_CONFIG_ITEM_TO_MASTER.master_id' is invalid
Robot was not attached to the Primary hub. It was attached to a different/secondary hub.
The UMP machine was no longer attached to the Primary hub. It could not be moved to the Primary without error using IM.
On the file system, restore the original robot.cfg which did point to the Primary Hub.
1. Stopped the UMP robot watcher service.
2. Restored the original robot.cfg which pointed to the Primary hub not the secondary
Once the robot.cfg was restored, then started, we logged in to UMP and USM loaded without error.