Usually, this problem happens because your Outlook profile is corrupted. Other possible causes include a damaged PST file, problems with syncing, or the address book being set up incorrectly. If you are using Outlook with Exchange, the issue might also be caused by Autodiscover not being set up right, or old settings in the registry that are blocking access to the address list. Before attempting these solutions, try using the same user profile on a different computer. If the problem continues on the second machine, contact your Organization’s IT Administrator for further assistance.
1: Use Online Mode in Outlook
Outlook can work in either Online Mode or Cached Mode when connected to an Exchange Server. In Cached Mode, data is stored locally, which can sometimes cause address book issues if things get out of sync. Switching from Cached Mode to Online Mode can often resolve the error.
2: Repair the PST File
When sending or receiving emails, Outlook uses the “.pst” file to store your data. If the .pst file becomes corrupted, it might cause problems with your address book. Microsoft provides a built-in tool called “SCANPST.EXE” to fix problems with PST files. The PST file location will vary depending on your Outlook and Windows version, and profile set up. Here are the typical default locations: After repairing the PST file, check if the Outlook Address Book starts to work correctly.
3: Enable Encryption of Data Between Exchange Server & Outlook
If the data transferred between the Exchange Server and Outlook isn’t encrypted, Outlook might prevent you from accessing the address book. Enabling encryption can fix this.
4: Empty the Autocomplete List
Outlook remembers addresses entered in the To, Cc, and Bcc fields to help you quickly address future messages. If this Autocomplete List is corrupted, it can cause errors with displaying addresses. Clearing it can help.
5: Repair Office/Outlook
If your Office or Outlook installation is corrupted, various features—including the Address Book—may fail to work. Running Office’s built-in repair tool can often resolve these problems. Note: This process repairs the entire Office suite, even if you just need to fix Outlook. If you use a standalone version of Outlook, search for it separately in Control Panel and follow the same repair steps.
6: Remove the Address Book and Add it Back
Sometimes, sync issues or a corrupted Address Book can cause this error. Removing and then re-adding the Address Book in Outlook might fix the issue. Note: If you don’t see the Outlook Address Book option, start from step 7 below. Important: If your address list was large, re-adding contacts manually can take time, and some entries might be lost.
7: Delete Offline Address Book Folder Contents
Outlook keeps a copy of your address books to access them offline. If there is a sync error or conflicting entries in this folder, problems may occur. Deleting the offline copy forces Outlook to rebuild it, which can solve display issues.
8: Delete the User Profile and Create a New One
A wrong or corrupted user profile in Outlook can also cause this error. Creating a new one may solve the issue. Note that this process will delete your current Outlook profile, so you will need to set up your account again.
