Does the user actually get removed from the database? That particular error is just the notification engine (the guy that does MWIs and message notification work) indicating that the user you asked to delete was not currently being monitored - which is a little unusual since when they're created they should be added to the monitor list. But if the user was created externally by a custom process directly through the DB or the like, this could happen. Anything like that going on here?
I have the exact same issue. For me the user does not get deleted. I have at least two users that I am trying to delete where this error occurs. These users were created either by Unity or by AD with an import to Unity.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...