How do you sign in if MS always show Uknown error (Office for Mac)

Question

How do you sign in if MS always show Uknown error (Office for Mac)

Alexander Horvath 0

Yeah thanks

I have latest MS Office

I log in properly. I have paid account in good standing. Nothing matters.

You just cannot sign it due to unknown error. And yes I have all latest packaged downloaded.

Moderator note: thread updated with operating system (macOS)

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3 answers

Your answer

Answer 1

Jeronimo Fuerte 46,010 Independent Advisor

Sorry to hear that you’re having trouble signing in. Could you please share a little more information about the issue? Where exactly are you trying to sign in: a Microsoft 365 application such as Word or Excel, the Microsoft 365 website, or another Microsoft service?

Also, when the “Unknown error” appears, could you please share a screenshot of the complete error message, making sure that no personal or sensitive information is visible?

Are you able to sign in successfully to your Microsoft account at https://account.microsoft.com using the same account?

Finally, is this happening on only one device, or do you receive the same error when trying from another device or web browser?

Alexander Horvath 0 Reputation points

2026-09-14T23:15:44.15+00:00

it is happening on my macbook. Login on microsoft online works. Also Office 365 online works. But whenever I go and Open Word, Excel or Powerpoint I get sign up/activate. I activate and boom Unknown error 0/0, which does not say anything. I must force quit and then re-do something it goes ok sometimes I need to restart the computer. And this has been going on for last three months. Check forums I am not the only one. That's why so many updates on Apple store.
Jeronimo Fuerte 46,010 Reputation points Independent Advisor

2026-09-14T23:19:06.63+00:00

Please attempt the steps available here:
https://support.microsoft.com/en-us/support/known-issues/unknown-error-0x0-license-not-found-error-microsoft365-macos

Answer 2

Michael Bruton 0

I tried all of these steps and I am still getting the same error and cannot edit/save new projects. How can I speak to someone about this issue?

Stefan Blom 352.1K Reputation points MVP Volunteer Moderator

2026-09-15T09:22:57.5633333+00:00

Michael, if the steps in this thread hasn't helped, I recommend that you start your own. Use the Ask a question option which you will find at the top of the Q&A page, next to your avatar. Sometimes, you have to click the menu icon and then click Ask a question.

Answer 3

it is happening on my macbook. Login on microsoft online works. Also Office 365 online works. But whenever I go and Open Word, Excel or Powerpoint I get sign up/activate.

Since you have a Microsoft 365 subscription, you should be able to install and activate Office locally on your Mac. You do need Microsoft 365 Personal, Family or Premium (or one of the corresponding business/organization subscriptions). In particular, note that 365 Basic won't let you install and license Office apps locally (Basic subscriptions include OneDrive storage and mobile apps only).

Which version of macOS do you have? You will need macOS 12 or later. Depending on your specific version of macOS, you may not be able to run the most recent Office release, though. See https://www.brandwares.com/bestpractices/2023/03/most-recent-office-you-can-run-best-practices/ .