Cannot open Microsoft 365 - Error 0x0 - Tried all Help Suggestions

Question

Cannot open Microsoft 365 - Error 0x0 - Tried all Help Suggestions

Lucille Wall 0

My Microsoft 365 is locked and every time I try to activate it it says "error 0x0." I tried to reinstall the package but it said I needed OS 14.0 or higher. I have OS 14.0 or higher. I tried opening the Microsoft AutoUpdate (MAU) from Finder > Applications > Microsoft AutoUpdate as per the help page and my Finder applications does not have a Microsoft AutoUpdate option. I've tried going to my library and doing the application support, that is not in my library. I've made sure there are no individual Microsoft updates available on my computer. I am at a loss.

Stefan Blom 351.7K Reputation points MVP Volunteer Moderator

2026-09-13T12:53:55.3933333+00:00

Are you able to start your Office apps, although they won't activate?

If you start Word and click Word > About Microsoft Word, which version number is shown?
Lucille Wall 0 Reputation points

2026-09-13T13:01:15.65+00:00

Yes, I can. It's 16.77.
Lucille Wall 0 Reputation points

2026-09-13T13:02:31.4366667+00:00

Also, when opening Word it does prompt me to do a MAU, but then it says, "Autoupdate cannot connect to the update server."

1 answer

Your answer

Stefan Blom 351.7K Reputation points MVP Volunteer Moderator

2026-09-13T12:53:55.3933333+00:00

Are you able to start your Office apps, although they won't activate?

If you start Word and click Word > About Microsoft Word, which version number is shown?
Lucille Wall 0 Reputation points

2026-09-13T13:01:15.65+00:00

Yes, I can. It's 16.77.
Lucille Wall 0 Reputation points

2026-09-13T13:02:31.4366667+00:00

Also, when opening Word it does prompt me to do a MAU, but then it says, "Autoupdate cannot connect to the update server."

Answer 1

Yes, I can. It's 16.77.

Also, when opening Word it does prompt me to do a MAU, but then it says, "Autoupdate cannot connect to the update server."

Thanks for the follow-up. Version 16.77 is too old. You should be able to install the most recent version of Office from the update history page at https://learn.microsoft.com/en-us/officeupdates/update-history-office-for-mac .

Also, install the most recent version of Microsoft AutoUpdate. See https://support.microsoft.com/en-us/office/office-for-mac/troubleshoot-microsoft-autoupdate-in-microsoft-365-and-office-for-mac .

For more on Office versions, have a look at John Korchok's article at https://www.brandwares.com/bestpractices/2023/03/most-recent-office-you-can-run-best-practices/ .