Fix: Excel Security Warning When Opening Files in OneDrive

Microsoft Aware of Security Prompt When Opening Excel Files in OneDrive for Business

Users of Microsoft Excel are encountering a security prompt when opening files from SharePoint or OneDrive for Business, a known issue acknowledged by Microsoft. The prompt, reading "This content presents a potential security issue. Do you trust this content?", appears for both .xls and .xlsx files in Excel 2019 versions 2309 and 2406. Excel 2021 users seem unaffected.

While identified as a "service degradation," the prompt serves as a temporary measure for another underlying issue. Microsoft is working on a permanent solution expected to roll out by August 13, 2024.

Temporary Workarounds:

Until the fix arrives, users can try the following workaround:

1. Mark SharePoint/OneDrive as a Trusted Site:

1. Search for "Internet Options" in the taskbar.
2. Go to the "Security" tab.
3. Click "Trusted Sites," then "Sites."
4. Add your SharePoint site address (e.g., https://yourcompany.sharepoint.com) and click "Add."
5. Close all windows and reopen the file from SharePoint.

Note: Organizational IT restrictions may prevent users from modifying these settings. Contact your IT administrator for assistance in such cases.

2. Administrators can implement the fix organization-wide:

1. Access the Group Policy Management Console.
2. Navigate to Windows Components > Internet Explorer > Internet Control Panel > Security Page.
3. Use the "Site to Zone Assignment List" policy.
4. Add the SharePoint or OneDrive domain (e.g., https://{your-domain-name}.sharepoint.com for SharePoint or https://{your-domain-name}-my.sharepoint.com for OneDrive).

Although a minor inconvenience, this security prompt disrupts workflows for frequent Excel and SharePoint users. The provided workaround offers a temporary solution until Microsoft implements a permanent fix.