If the update mechanism appears to be broken for you, it could be because of a corruption in your OAB or in your mail profile.
In that case, you can completely reset it by deleting the files making up the OAB or by recreating your mail profile.
To solve this issue, you need to do the following steps.
Start Adsi Edt (be careful with this change) Go to default Naming Context Microsoft Exchange System objects Open the properties of the objects which gave the warning in the Power Shell message.
This means that in the worst possible scenario, an update to the Address Book won’t become available to the user until 48 hours after the change.
This situation however is extremely rare since the default maintenance time on Exchange is at AM and updates and downloads are usually performed during working hours.
Another way to make sure that you get a fresh copy of the OAB is by renaming the oab-files to when Outlook is closed.
They are stored in the following location: which itself holds subfolders with named after Account GUIDs.
I might have a problem with my Offline Address Book in Outlook.
For me, new colleagues are not showing up and the contact pictures aren’t displaying either.
The command for the manual update procedure can be found here: Outlook will automatically download updates only unless the size of the changes is larger than 12.5% (one-eighth) of the total OAB size.