Voicemail Cutoff

I have two extensions with a problem…
Voicemail cuts out after a few seconds of "I’m sorry the person…"
Voicemail is enabled what could be the problem other extensions are OK…
Must be something really simple just can’t see it…

One of the extensions has had voicemail before the other is new…

Thanks…

It only happens with the “Unavailable message” and only when it is the default message, if you change the default message it works…but why I wonder ?