Just a guess here, but was a Primary Extension defined for this user?
Clip ***In the Primary column, use the drop-down menu to select a primary extension for that subscriber.
The primary extension is the mailbox for receiving, saving, and retrieving voice-mail messages. If no primary extension is designated for a subscriber, that subscriber cannot receive, save, or retrieve voice-mail messages.
In this field, None means that none of the displayed extensions for the subscriber is the primary extension. You can designate a mailbox for this subscriber now, but the subscriber cannot access it until you configure the subscriber's primary extension at a later time.
I now found a workaround. There was a problem with the passwords and pins of the users. After changing them the mailbox was accessible again. Seems to be a bug or something like that. Maybe there was no Pin configurated for some of the useres before.
I'm not able to access my old voice mail messages all of a sudden. The recording says something like 'the message is currently not available'. This has never happened before in all the years I have been using this system. I have t...