Ive had this issue before with a couple of users.
Best way to overcome this is to just rebuild the appdata (if that doesnt cause too many issues)
if it does then i believe if you delete all the protect folder from appdata it should force it to work again.
Then start up outlook, type in the the username and password and it will work again. :)
cheers, deleted the protect folder and hes still getting the pop up randomly :(
when you say randomaly? is that like one in every 2 tries or like once every 10-15?
also do they logoff and log back in when testing this? (if so roaming or local profile and or folder redirection)?
this might bring up some good logs to look through
i would possibly try rebuildign the whole of the appdata for the user if you can
We were / are getting this too but I haven't fully troubleshooted why. Creating a new outlook profile seemed to fix the problem which presented itself firstly when we forced the password changes at the beginning of term for staff.
Entering their credentials didnt work fully until they entered domain\username with their password, but again it was inconsistent as some went away after they entered their credentials, others it kept coming back.
Upgrading to 2013 seemed to fix the problem on a couple I tested too.
Ill dig up my old thread hold on.
We use to have this, there is a hotfix out for this which we deployed through out network and it fixes the problem. The update is KB2584053. Hope this helps. http://support.microsoft.com/kb/2584053
Our problem is strange, only currently effecting 4 users, it doesn't come up straight away when opening outlook, it just comes up at random point during the day. User enters their password and it goes away again for a few hours before returning. On average coming up about 4 times a day.
I will give the hotfix a go and report back. If that doesn't work, I will delete the users app data folder or give them a new profile and see how they get on with that.