Excel requires activation but activation fails with unknown error 0x0

Question

Excel requires activation but activation fails with unknown error 0x0

Florian F 0

Excel suddenly requires that I "Activate Microsoft 365 to Create and Edit". I cannot save anything.

When I click "Activate" and sign in it says "Locating for Licenses...", then "Activating...",
but then "Unknown Error - An unknown error has occurred. The error code is 0x0"
and finally "Unable to Activate Microsoft 365" and Excel remains read-only.

The "About" popup says "Belongs to: (my email)" but "Licence: Not activated". Version is "16.78.3".

If I log in to my microsoft account It displays a valid license for Office version 16.

What can I do to get out of this very annoying situation?

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3 answers

Your answer

Answer 1

MacPRG 0

Hi. Had similar problem with Office 2021 perpetual licence on Monterey Mac running Excel version 16.78.

Licence stopped working this week (apps go into view only mode). Followed all Microsoft advice to uninstall, run remove licence tool and download from Account. Not worked. Auto update also failed to resolve. Licence failed to activate and download 16.110 wouldn't run on Monterey. Was told Monterey is the problem and to contact Apple to upgrade.

Solution: Trial and error led to https://learn.microsoft.com/en-us/officeupdates/update-history-office-for-mac. Downloaded September 17, 2024, 16.89.1 (24091630) and reinstalled over existing (didnt need to uninstall). Activate login worked and 2021 perpetual licence now back in place. Repeated the same on a Tahoe OS Mac and also now working. Hope this might help someone.

Florian F 0 Reputation points

2026-07-24T11:18:12.1833333+00:00

Thanks for the answer, but it didn't work for me. It just says "No licence found".
From what I read somewhere else, my "perpetual licence" isn't valid after version 16.78.3. And that version contains a certificate now expired.
Microsoft could fix the problem with a workaround. Or publish an update to install manually.

Answer 2

Goddumarri Vijay Kumar 0

I am facing similar issue

Office 2019
mac 26.5.1 (25F80)

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Answer 3

DaveM121 918.5K Independent Advisor

There are a couple of on-going problems with the Office apps on an Apple Mac at the moment due to the July 13 update

1

What version of Microsoft Office do you have, is that a subscription to Microsoft 365 or a standalone version of Office like Office 2019, 2021 or 2024.

2

At the top left of your Desktop, click the Apple icon and select 'About this Mac', what version of MacOS is installed on your computer?

Florian F 0 Reputation points

2026-07-21T06:58:19.4866667+00:00

Office Home & Business 2019 for Mac.

"About MS Excel" says "Version 16.78.3".

"About this Mac" says "Tahoe 26.5.2".
DaveM121 918.5K Reputation points Independent Advisor

2026-07-21T07:04:54.3+00:00

Thank you for that information.

If your Office licence is Office Home and Business 2019, then this is caused by the July 13 update, after that update, the 2019 version of Office will go into Read Only mode, because the licensing certificate can no longer be updated on that version of Office.

They provide full details on that July 13 update on this link.

https://support.microsoft.com/office/update-microsoft-365-or-office-on-your-macos-or-ios-device-f418ae5d-bb5f-4078-b3d9-9340f5dd084e
Florian F 0 Reputation points

2026-07-21T10:44:39.4066667+00:00

Does it mean Microsoft forces me to buy Office again ?

Is there a way to restore the pre-july 13 update?

If not, it is bye bye for all Microsoft products.
DaveM121 918.5K Reputation points Independent Advisor

2026-07-21T10:50:22.61+00:00

They indicate on that link there is no longer a workaround to get Office 2019 working after that update and no-one has found a method to go back before that July 13 update.
Florian F 0 Reputation points

2026-07-21T11:02:26.92+00:00

Not the answer I was looking for, but thank you for the information.
DaveM121 918.5K Reputation points Independent Advisor

2026-07-21T11:03:21.2533333+00:00

Glad to help!
Florian F 0 Reputation points

2026-07-22T04:53:32.98+00:00

For what it's worth, I switched to WPS Office. Problem solved.
DaveM121 918.5K Reputation points Independent Advisor

2026-07-22T05:09:57.45+00:00

I am glad you found a solution that suits your needs.