Additional file-related features and issues within Microsoft Teams for Education
The message “sign in is not complete” when opening files in Teams usually indicates an authentication or cookie/URL trust issue between Teams and the underlying Microsoft 365 services (SharePoint/OneDrive).
Try these steps in order:
- Fully sign out and back in to Teams
- In Teams, select the profile picture > Sign out.
- Close Teams completely (make sure it is not running in the taskbar).
- Reopen Teams and sign in with the same work account used for email/OneDrive.
- Clear the Teams cache again (Windows and Mac)
- Quit Teams.
- On Windows: in File Explorer, go to
%appdata%\Microsoft\Teamsand delete all contents of that folder, then restart Teams and sign in. - On Mac: quit Teams, then delete
~/Library/Application Support/Microsoft/Teams, then restart Teams and sign in. - This removes cached auth and file access data and forces a fresh sign-in.
- Check browser cookie settings (for web-based auth inside Teams)
If using Teams in a browser, or if embedded web views are used for file access:
- In Chrome: go to Settings > Site settings > Cookies and site data.
- Select Allow all cookies and ensure Block third-party cookies is not selected.
- Under Sites that can always use cookies, add:
-
microsoft.com -
microsoftonline.com
-
- In Safari (macOS or iOS): disable Prevent cross-site tracking in Settings/Preferences > Safari > Privacy. These settings ensure Microsoft Entra ID and SharePoint/OneDrive cookies can be used so sign-in completes.
- In Chrome: go to Settings > Site settings > Cookies and site data.
- Validate Teams/Office 365 URLs are allowed on the network
- Ask the IT admin to verify that all required Microsoft 365 and Teams URLs and IP ranges are allowed through firewalls and proxies, as documented in Microsoft 365 URLs and IP address ranges.
- Misconfigured proxies or blocked URLs can cause incomplete sign-in when opening files.
- If using Edge/Internet Explorer to open files
- In Internet Options:
- Under Privacy > Advanced, accept First-Party and Third-Party cookies and check Always allow session cookies.
- Under Security > Trusted Sites > Sites, add:
-
https://login.microsoftonline.com -
https://*.teams.microsoft.comThis prevents sign-in loops when Teams or file views rely on the browser engine.
-
- In Internet Options:
- If the issue is only with files shared in 1:1 or group chat
- Files shared in chat are stored in the sender’s OneDrive. If the error appears only on those files, the OneDrive site may have Limited-access user permission lockdown mode enabled.
- Ask the file owner (or the admin) to:
- Sign into their OneDrive site.
- Go to Settings (gear icon) > OneDrive Settings > More Settings.
- Under Features and storage, select Site Collection Features.
- Find Limited-access user permission lockdown mode and select Deactivate.
- After this, retry opening the file from Teams.
- Involve the IT admin if the problem persists
- There may be a tenant-level Microsoft Entra ID or SharePoint/OneDrive configuration issue preventing sign-in completion. The admin can review sign-in logs and run the Teams/SharePoint diagnostics in the Microsoft 365 admin center.
References: