Problems activating Microsoft 365 apps on new 24" iMac – they were activated, but now it's asking me to activate again but won't do it when I try

Question

Problems activating Microsoft 365 apps on new 24" iMac – they were activated, but now it's asking me to activate again but won't do it when I try

Tricia D 0

Hi. I have a new 24" iMac, and I use Microsoft 365 for Mac. I had already activated Outlook and Word, but today it asked me to activate them again, and when I tried to log in to Microsoft, it said 'An unknown error has occurred 0x0". I could not log on. I could not open Word or Outlook. I tried using the tool that's meant to remove the licensing, in case that was the issue, downloaded it but then it didn't run, and I couldn't find it on the system. I need both Word and Outlook to do my job.

frankie collard 10 Reputation points

2026-07-14T20:17:58.7366667+00:00

Hi there I’m on australia too.. I have done this twice and removed the old license and put it in the trash it has not unfortunately been working for me either… I can access it on my phone and I can log into excel online but I still cannot activate it on my Mac computer.
Tricia D 0 Reputation points

2026-07-14T21:28:33.39+00:00

Hi Frankie, I couldn't remove the licence with the licence removing tool, and I tried the procedure Sumit suggested for you – there was no Group Containers folder, but I did the rest of it – and that did not work either. Waiting to see if Sumit has more suggestions for me.

5 answers

Your answer

frankie collard 10 Reputation points

2026-07-14T20:17:58.7366667+00:00

Hi there I’m on australia too.. I have done this twice and removed the old license and put it in the trash it has not unfortunately been working for me either… I can access it on my phone and I can log into excel online but I still cannot activate it on my Mac computer.
Tricia D 0 Reputation points

2026-07-14T21:28:33.39+00:00

Hi Frankie, I couldn't remove the licence with the licence removing tool, and I tried the procedure Sumit suggested for you – there was no Group Containers folder, but I did the rest of it – and that did not work either. Waiting to see if Sumit has more suggestions for me.

Answer 1

Sumit D - IA 173.4K Independent Advisor

Hi,

Sincere apologies for the trouble you are having. I am seeing a lot of similar issues today, so something is at the backend causing this.

I'm going to run through a few steps with you. Some of these are diagnostic — they help me narrow down what's wrong, not fix it outright. So if nothing changes after a step, that's normal and expected, not a dead end. I'll keep going until we've got this resolved.

May I know the Mac version you are running? Is it fully updated?
Is it a Microsoft 365 subscription or an Office standalone?

Microsoft made some changes as discussed at https://yourwindowsguide.com/2026/07/microsoft-365-for-mac-not-working.html but it should not affect any new machine.

I look forward to hearing from you to get the results of the troubleshooting.

A Windows MVP writes content on the above website, so it is safe. However, do watch out for the ads. It should translate into your Browser language automatically.

frankie collard 10 Reputation points

2026-07-14T09:30:09.81+00:00

This has happened to me and I’m also having problems did your issue get fixed?
Tricia D 0 Reputation points

2026-07-14T11:08:56.3833333+00:00

Hi. It's a new iMac, running Tahoe 26.5.2. And I have a Microsoft 365 subscription.
Tricia D 0 Reputation points

2026-07-14T11:09:46.5766667+00:00

Look forward to the troubleshooting.
Tricia D 0 Reputation points

2026-07-14T11:10:34.5866667+00:00

I'm in Australia, btw, so if you don't hear back from me quickly, it may be because of the different time zone.

Answer 2

Sumit D - IA 173.4K Independent Advisor

I'm so glad to hear this, Tricia, that your problem is resolved. Count on us for any other Microsoft-related issues in the future. Have an awesome rest of the week!

Tricia D 0 Reputation points

2026-07-16T03:18:16.9966667+00:00

Thanks, Sumit. You too!
Sumit D - IA 173.4K Reputation points Independent Advisor

2026-07-16T14:48:21.7433333+00:00

Thanks.

Answer 3

I fixed this one myself. I saw somewhere in the online help that you needed to reinstall the Microsoft 365 apps. I had already removed all old Office stuff from my iMac. I went to my Microsoft account, to the Subscriptions page, to Install, and reinstalled Microsoft 365. It's working for now! That is, I can get into and send and receive emails in Outlook. I can create and save and modify Word files. Fingers crossed it stays fixed!

Thanks for your help, Sumit. Even though the things you'd suggested so far hadn't worked, it meant a lot to actually have a human being on the end of the line trying to help me.

Answer 4

Sumit D - IA 173.4K Independent Advisor

No problem.

On Mac, remove the Microsoft Office licensing files using these steps:

Quit all Microsoft Office applications.

Open Finder > Go > Go to Folder... and navigate to:

/Library

Open the Group Containers folder.

Delete the following folders if they exist:

UBF8T346G9.Office
UBF8T346G9.OfficeOsfWebHost

Go back to Go to Folder... and open:

/Library/Preferences

Delete:

com.microsoft.office.licensingV2.plist

(If present.)

Empty the Trash.

Restart the Mac.

Open an Office app and sign in with the Microsoft account associated with your license to reactivate Office.

0 comments

Answer 5

Sumit D - IA 173.4K Independent Advisor

Thanks, Tricia. I can understand it is an issue from the backend since @frankie collard is also having the issue.

Can you remove the license files and try to activate again, in a hope it works?

https://support.microsoft.com/en-us/microsoft-365-activation-licensing/how-to-remove-office-license-files-on-a-mac

frankie collard 10 Reputation points

2026-07-14T11:25:42.6266667+00:00

Iv removed the license a couple of times and tried to activate again, iv had no luck been trying for hours.
Tricia D 0 Reputation points

2026-07-14T13:13:10.0433333+00:00

Hi Sumit. I already tried this. The Mac License Removal Tool downloaded, but then did not start working by itself, and I couldn't find it anywhere on my computer to manually open it/get it going. I'm about to head for bed (it's late here in Australia) but will check back for your response in the morning.
Tricia D 0 Reputation points

2026-07-14T13:13:29.31+00:00

Hi Sumit. I already tried this. The Mac License Removal Tool downloaded, but then did not start working by itself, and I couldn't find it anywhere on my computer to manually open it/get it going. I'm about to head for bed (it's late here in Australia) but will check back for your response in the morning.
Tricia D 0 Reputation points

2026-07-14T21:17:08.4233333+00:00

Hi Sumit. I already tried this. The Mac License Removal Tool downloaded, but then did not start working by itself, and I couldn't find it anywhere on my computer to manually open it/get it going. I'm about to head for bed (it's late here in Australia) but will check back for your response in the morning.
Tricia D 0 Reputation points

2026-07-14T21:17:43.4566667+00:00

Sorry, that was an old comment that I could not get to load last night – I'm up again now.
Tricia D 0 Reputation points

2026-07-14T23:41:30.74+00:00

Hi. I just tried again to remove the licence files, but what happens is that I download the license removal package, and then it says to open a Microsoft 365 application to get it started, and when I try to open Outlook it asks me to log in, I put in my email, I put in my password, the same weird "You have reached a page that is not usually shown" message flashes up, and then I end up at the Unknown error message.
frankie collard 10 Reputation points

2026-07-14T23:47:55.1066667+00:00

Hey Tricia I’m having the same issues and can’t seem to get this resolved iv tried the license removal about 5 times now.. and mine is still not letting me activate my excel or word.
frankie collard 10 Reputation points

2026-07-14T23:49:08.6566667+00:00

It will also let me access everything on my phone but not on my Mac.
Tricia D 0 Reputation points

2026-07-15T00:17:26.34+00:00

Frankie, I ended up ditching all the old Office files on my desktop, then reinstalling Microsoft 365 from the Subscriptions page, where it says Install. Everything is working right now.
frankie collard 10 Reputation points

2026-07-15T00:55:09.34+00:00

Thanks so much I’ll try that now thank you for letting me know muchly appreciated.
Tricia D 0 Reputation points

2026-07-15T01:19:45.0433333+00:00

No worries! Let me know if it works. When I said 'on my desktop', I meant 'on my desktop computer', i.e. the iMac.