Comment 13 for bug 1858693

I've encountered something similar.

I'm trying to migrate a model from a Xenial to a Bionic controller. Both controllers are on Juju 2.9.37, the latest stable 2.9 series Juju at the time of writing.

Please see the attachment for details, but:

* The model status shows that my attempted migration failed due to a missing unit - which no longer exists, and hasn't existed for some time!
* The graylog-mongodb app only has a single unit, but it is not the leader.