To update your offline address book.
Temporary fix during change moratorium
Use the following steps
C:\Users\user.name\AppData\Local\Microsoft\Outlook -- (username is firstname.surname)
In there is a folder called offline address books
Close outlook first and rename this folder to old-Offline Address books.
then re-open outlook
if the folder will not rename then you have something associated with outlook still open - like an attachment.
if you cannot see a folder called ‘appdata’ then.
click on organize on top left.
click on folder and search options
click on view
Select the item to show hidden files, folders and drives, located just below the heading 'hidden files and folders.