Outlook Not Opening or Red "Unlicensed" Banner — Mac

Section: Email & Microsoft 365 Tags: outlook, mac, unlicensed, red-banner, not-opening, m365, office, keychain Source tickets: #25945, #27473 Confidence: High

Symptom

Outlook on macOS shows a red bar across the top reading "Unlicensed Product" or "Your subscription has expired". Alternatively, Outlook launches but immediately crashes or refuses to open. The user's M365 licence is confirmed active in the admin portal.

Variants:

"Microsoft 365 is unlicensed" despite valid subscription
Outlook opens read-only only
Outlook quits on launch with no error message
Password prompt for shared mailboxes on every launch after a keychain reset

Root Cause

The activation token for Outlook is stored in macOS Keychain. If the Keychain entry is corrupt, expired, or was removed (e.g., during a keychain reset or OS upgrade), Outlook cannot verify the licence locally and shows the red banner — even though the server-side licence is valid.

A secondary cause is a corrupt Outlook identity/profile database.

Remediation Steps

Step 1 — Sign out and back in to Office

Open any Office app (Word is easiest if Outlook won't open)
Word → Sign Out (from the top right of the Word window or from the menu)
Relaunch Outlook → Sign in with the user's M365 email and password
Wait 2–3 minutes for activation to complete

Expected result: Red banner disappears after sign-in. Risk: None.

Step 2 — Remove Microsoft credentials from Keychain

Open Keychain Access (Applications → Utilities)
Search for Microsoft — select all results → delete
Search for Office — delete all Office-related entries
Search for com.microsoft — delete if found
Relaunch Outlook → sign in when prompted

Expected result: Fresh credential stored; activation completes.

Step 3 — Reset the Office licence

Close all Office apps completely (Cmd+Q each one, check Activity Monitor)
Open Terminal and run:

sudo rm -rf ~/Library/Group\ Containers/UBF8T346G9.Office/

⚠️ Warning: This removes the Outlook local database cache. Outlook will re-download all email from the server after this step. For very large mailboxes this can take 30–60 minutes.

Relaunch Outlook → sign in
Wait for initial mailbox sync to complete

Expected result: Office activates with a clean licence state. All email is re-downloaded from the server (no data is lost — it's all server-side). Risk: Caution — confirm the mailbox is on Exchange Online or M365 (server-side) before running this. Do not run this if the user has local-only (POP3) mail not backed up elsewhere.

Step 4 — Reinstall Office

If Steps 1–3 fail:

Download and run the Microsoft Office Removal Tool
Reboot
Install Office fresh from https://portal.office.com → Install apps
Sign in with M365 credentials on first launch

Verification

Open Outlook. The red banner should be gone. Go to Outlook menu → About Microsoft Outlook — confirm it shows the user's name and email address indicating a valid, signed-in state. Send a test email.

If This Fails

If Outlook continues to show unlicensed after a clean install and sign-in:

Confirm in admin.microsoft.com → Users → [user] → Licences that an Exchange Online or M365 licence is assigned
Try signing in on a different Mac with the same credentials — if it works there, the issue is machine-specific (consider creating a new macOS user account and testing)
Raise a Microsoft Support ticket via admin.microsoft.com → Support