cannot access contacts in outlook classic

Hi FRANK

Thank you for posting your question in Microsoft Q&A.

Based on your description, I would like to share some information that I hope will help you that since you have confirmed you are the owner of the mailbox and have full rights, this error message is misleading. It usually indicates that the local data cached on your computer has become out of sync with the server, rather than an actual restriction on your account.

Given that you are running a Windows 11 Insider Preview (Build 26200), it is highly likely that a system update has caused a permissions conflict with your local Offline Address Book (OAB) files.

Here is recommendation you can try:

Reset the Offline Address Book Permissions: This solution forces Outlook to create a fresh copy of your address book cache, which can resolve the permission conflict on your local drive.

• Close Outlook completely > Right-click the Start button and select Run > Copy and paste the following path into the box and press Enter: %localappdata%\Microsoft\Outlook\Offline Address Books
• In the folder that opens, you will see a sub-folder (usually named with a long string of numbers/letters, or simply v4).
• Right-click that sub-folder and select Rename > Change the name to end in .old (ex: rename v4 to v4.old).
• Restart Outlook.

Outlook will automatically create a new folder and download a fresh copy of the address book. Once the update is complete (usually 1-2 minutes), please try creating the contact again.

Additionally, you can read more about this specific error behavior in Microsoft official troubleshooting guide here: Error when adding contacts to contacts folder - Microsoft Outlook | Microsoft Learn

(Note: While this article references previous versions, the information regarding Offline Address Book corruption also applies to Windows 11).

If the issue persists after these steps, you can consider rebuilding your main Outlook data file (.ost), In the meantime, you can successfully add contacts via Outlook on the Web to ensure your work is not interrupted.

I hope these suggestions provide some helpful ideas. If you need further assistance, feel free to ask via comments section.

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