Exchange backup fails with a 'Unable to login' error message. (4033457)

The following backup error occurs when using the Exchange Plugin:

1] Job Message   2014/03/12 21:00:00   64   Data Plugin   GLOSCITYS300   Plugin: 'Exchange Server APM', Version: '4.6.8'
2] Job Message   2014/03/12 21:00:00   64   Data Plugin   GLOSCITYS300   Preparing a Full Backup, mode Normal
3] Error   2014/03/12 21:00:00   64   Data Plugin   GLOSCITYS300   Unable to login

So the Exchange Plugin is trying to login to the Exchange Server and then finally the connection is lost, as the backup cannot login to the Exchange Server:

"Job manager lost message channel unexpectedly"

As per the Exchange Plugin User Guide on the following link, you have to make sure that all steps in Chapter 4 and 5 are implemented and configured correctly, otherwise the Exchange Plugin cannot login into the Exchange Server and access the instances to back them up:

https://support.quest.com/netvault-backup/technical-documents

It could also be possible that the Exchange Plugin was configured with login details, but someone had changed them on the Exchange Server, therefore the Exchange Plugin login details are incorrect and need to be changed.

The problem in this instance was that the customer deactivated an account and therefore created a new account and used it for the Exchange Plugin to resolve the issue.