I have been using Microsoft 365 through my employer on my iMac. Suddenly today (was using the exchange email earlier today) I keep getting a pop up box saying error 9n155. My computer is connected to the internet. I did not do any updates today. I am unable to send or receive email.

Hi @Kathryn Nuss , Welcome to the Microsoft Q&A platform! I'm sorry to hear that you're experiencing this issue with Microsoft 365 on your iMac. Here are a few steps you can try to fix this error: Sign out and sign back in: Open any Microsoft 365 app like Outlook. Go to File > Account > Sign Out. Close the app, reopen it, and then sign back in. Clear your credentials: Open Keychain Access on your iMac. Search for any entries related to Microsoft Office and delete them. Restart your computer and try to sign in again. Even if you didn't update manually, it's a good idea to check if there are any pending updates. Open any Microsoft 365 app and go to Help > Check for Updates. Sometimes creating a new profile can fix the problem. Open Outlook > Preferences > Accounts > + to add a new account. Download and run the Microsoft Support and Recovery Assistant to troubleshoot and fix the problem. Please feel free to contact me for any updates. And if this helps, don't forget to mark it as an answer. Best, Jake Zhang

I keep getting a pop error message 9n155. How can this be resolved?

Accepted answer

Jake Zhang-MSFT 6,850 Reputation points Microsoft Vendor

2024-11-05T02:26:37.11+00:00
Hi @Kathryn Nuss ,

Welcome to the Microsoft Q&A platform!

I'm sorry to hear that you're experiencing this issue with Microsoft 365 on your iMac. Here are a few steps you can try to fix this error:

Sign out and sign back in:

Open any Microsoft 365 app like Outlook.

Go to File > Account > Sign Out.

Close the app, reopen it, and then sign back in.

Clear your credentials:

Open Keychain Access on your iMac.

Search for any entries related to Microsoft Office and delete them.

Restart your computer and try to sign in again.

Even if you didn't update manually, it's a good idea to check if there are any pending updates.

Open any Microsoft 365 app and go to Help > Check for Updates.

Sometimes creating a new profile can fix the problem.

Open Outlook > Preferences > Accounts > + to add a new account.

Download and run the Microsoft Support and Recovery Assistant to troubleshoot and fix the problem.

Please feel free to contact me for any updates. And if this helps, don't forget to mark it as an answer.

Best,

Jake Zhang
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Jake Zhang-MSFT 6,850 Reputation points Microsoft Vendor

2024-11-13T01:39:01.0866667+00:00

Hi @Kathryn Nuss ,

Please kindly consider this comment as a warm follow up, I want to know if your problem has been solved. If you still have any other questions, please feel free to comment here and I'm glad to provide further support.If the above info is helpful to this question, you can click "Accept Answer". Have a nice day!

Best,

Jake Zhang

Mezoff, Ethan 0 Reputation points

2024-11-13T03:51:46.09+00:00

Hi Jake - I'm getting the same error (below) on my MacBook Pro and iMac personal devices when using the Outlook app over the past ~week. I've tried the above steps to no avail. I contacted my company's IS help desk but they're unable to help. The Outlook app on personal devices is very important to my workflow efficiencies so I'm hoping there's a fix.

Correlation Id: 98402eb4-cf2f-4747-933d-4bb2be203b56

Timestamp: 2024-11-13T03:43:34.000Z

DPTI: 4a67a4f954fd201be689cc3b9aab2121b5363c7f8c173168bd08647bbae11e39

Error Tag: 9n155

Error Code: 0

Kathryn Nuss 25 Reputation points

2024-11-13T12:47:28.7+00:00

The suggested instructions did not correct the issue of the error. My sense something is corrupt in the authentication process. I am running Sequoia 15.1 on my devices. the other user on this string Ethan Mezoff works at the same hospital system and was told the help desk could not identify the error. Interestingly I am able to run outlook office on a web browser but not using the outlook app on my devices

Kathryn Nuss 25 Reputation points

2024-11-13T12:50:35.7666667+00:00

I cleared the affected account and am I now unable to add it back as an authenticated email account

Jake Zhang-MSFT 6,850 Reputation points Microsoft Vendor

2024-11-15T09:24:21.01+00:00

Hi @Kathryn Nuss ,

Thanks for your response!

This sounds like a frustrating situation, especially since you can access Outlook over the web, but not through the app. Given that you are running macOS Sequoia 15.1, there may be a compatibility issue or a deeper problem with the authentication process. Here are some additional steps you can try:

Completely uninstall Microsoft Office from your iMac. Reinstall the latest version from the Microsoft 365 portal.

Reset Keychain Access:

Open Keychain Access.

Delete any entries related to Microsoft Office.

Restart your iMac and try to add your account again.

Restart your iMac in safe mode by holding down the Shift key during startup. Try opening Outlook and adding your account in safe mode.

Please feel free to contact me for any updates. And if this helps, don't forget to mark it as an answer.

Best,

Jake Zhang

Kathryn Nuss 25 Reputation points

2024-11-15T11:55:35.15+00:00

Thanks for your continued interest in my issues. I will try this today and let you know!

Jake Zhang-MSFT 6,850 Reputation points Microsoft Vendor

2024-11-18T09:54:05.6066667+00:00

Hi @Kathryn Nuss ,

Is there any update on this thread? If the issue has been resolved, please mark the helpful replies as answers, this will make answer searching in the forum easier and be beneficial to other community members as well. Thanks for your understanding.

Best,

Jake Zhang

Kathryn Nuss 25 Reputation points

2024-11-18T11:57:17.2533333+00:00

The other user on here called our help desk for the same issue. He said they didn't have a solution to the error but were going to work on it. We both removed the keychain credentials a couple of days ago and the error disappeared!! We think the IS team at our hospital may have identified the issue on their end in the mean time. All is well! We appreciate your persistence on making this right! All of our Macs on the business network are now operating as expected! Thanks for all of your help!!

Kainat Khawaja 0 Reputation points

2024-11-20T10:37:56.04+00:00

Hi @Jake Zhang-MSFT

I have a similar problem when using my university account with the following error:

Something went wrong. [9n155]

Correlation Id: 34a8c7e9-f5c5-4095-84c2-44caf58f8f39

Timestamp: 2024-11-20T10:33:48.000Z

DPTI: ab12d33d12135a25fbe081b580d2fc53adb713fd59d53a18646d0884ba4ebad9

Error Tag: 9n155

Error Code: 0

I am able to login through a different account to Microsoft Teams, and also with this same university account on the Web browser (although one time I couldn't), but the university account yields this error on my Mac Microsoft Teams app.

I have tried all the instructions mentioned above, to no avail. The university IT department is also stumped.

I deleted Keychain credentials, restarted my Mac, checked for updates, uninstalled and reinstalled the app more than once.

Please let me know what else I can try?
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I keep getting a pop error message 9n155. How can this be resolved?

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