One of our users (Windows XP Pro & Outlook 2003) came across an issue that when he attempts to access the address book he receives the following error message:
The messaging interface has returned an unknown error. If the problem persists, restart Outlook.
All other functionality appears to be fine within Outlook. Only accessing the address book seems to be at issue
Reading through the articles here, I initially tried to create a new Exchange profile, yet still received the same error message. Then I started Outlook from the Run prompt using 'Outlook /safe' and I was successful in opening up the address book.
So I am now wondering what I can do for a permanent fix so we do not have to run Outlook in safe mode.