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

Question

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.

Answer 1

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:

1. 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.

2. 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.

3. 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.

4. Sometimes creating a new profile can fix the problem.

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

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

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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