Can't login to Outlook and MS Teams

Question

Can't login to Outlook and MS Teams

Arnel Valero 5

I can't login outlook and Teams. Here is the error. Please check.

Correlation Id: PII removed

Timestamp: 2025-10-16T21:37:06.000Z

DPTI: PII removed

Message: An unexpected error occurred.

Tag: 7q6ch

Code: 3221815318

Alexis-NG 18,065 Reputation points Microsoft External Staff Moderator

2025-10-17T17:33:38.67+00:00

Hi @Arnel Valero,

Hope things are running smoothly on your end. Following up on the support thread we've been working on. I hope the information I shared in my previous answer resolve the issue you were facing. If you are still facing the same issue or need assistance with anything else, kindly respond to this email, and I will be happy to help. We want to make sure everything is working as expected and that your experience remains uninterrupted.

Thank you for your patience and understanding throughout the troubleshooting process.

I look forward to hearing from you soon.
Mike Fleet 0 Reputation points

2025-10-17T18:09:07.0766667+00:00

@Alexis-NG Nothing you suggested helped me I'm afraid, nothing on the business users account has changed, they're still licensed. Only Outlook is affected, everything else from the 365 suite runs fine including Teams. Windows 11 24H2.

Similar happened on Monday morning when lots of people were unable to access Microsoft 365 apps and some machines were even blue screening as a result of Outlook crashing which is why I raised it with Microsoft. It was resolved in an hour or so.

I spent a good hour troubleshooting this morning with no resolution. Submitted as issue to Microsoft and it was rejected. Uninstalled Office, renamed AppData folders and reinstalled with no joy.

Luckily New Outlook works so we have a workaround. I'll pick up again next week, might try clearing out Temp folders and/or do another uninstall and check for remnants of the install before trying again.
Alexis-NG 18,065 Reputation points Microsoft External Staff Moderator

2025-10-20T15:29:42.0366667+00:00

Hi @Arnel Valero,

I hope you are having a great day so far.

It was truly a pleasure working with you on this thread. I understand that you might have other important matters at hand to attend to and do not have convenient time for this at the moment. If you're still encountering any problems or have run into new challenges, please let me know which steps you're currently stuck on and happy to provide further help whenever you need it.

If you have any further questions, feel free to tag me in your reply so I can assist you directly.

Looking forward to your update.

2 answers

Your answer

Alexis-NG 18,065 Reputation points Microsoft External Staff Moderator

2025-10-17T17:33:38.67+00:00

Hi @Arnel Valero,

Hope things are running smoothly on your end. Following up on the support thread we've been working on. I hope the information I shared in my previous answer resolve the issue you were facing. If you are still facing the same issue or need assistance with anything else, kindly respond to this email, and I will be happy to help. We want to make sure everything is working as expected and that your experience remains uninterrupted.

Thank you for your patience and understanding throughout the troubleshooting process.

I look forward to hearing from you soon.
Mike Fleet 0 Reputation points

2025-10-17T18:09:07.0766667+00:00

@Alexis-NG Nothing you suggested helped me I'm afraid, nothing on the business users account has changed, they're still licensed. Only Outlook is affected, everything else from the 365 suite runs fine including Teams. Windows 11 24H2.

Similar happened on Monday morning when lots of people were unable to access Microsoft 365 apps and some machines were even blue screening as a result of Outlook crashing which is why I raised it with Microsoft. It was resolved in an hour or so.

I spent a good hour troubleshooting this morning with no resolution. Submitted as issue to Microsoft and it was rejected. Uninstalled Office, renamed AppData folders and reinstalled with no joy.

Luckily New Outlook works so we have a workaround. I'll pick up again next week, might try clearing out Temp folders and/or do another uninstall and check for remnants of the install before trying again.
Alexis-NG 18,065 Reputation points Microsoft External Staff Moderator

2025-10-20T15:29:42.0366667+00:00

Hi @Arnel Valero,

I hope you are having a great day so far.

It was truly a pleasure working with you on this thread. I understand that you might have other important matters at hand to attend to and do not have convenient time for this at the moment. If you're still encountering any problems or have run into new challenges, please let me know which steps you're currently stuck on and happy to provide further help whenever you need it.

If you have any further questions, feel free to tag me in your reply so I can assist you directly.

Looking forward to your update.

Answer 1

Mike Fleet 0

Also seen this on a device this morning.

Correlation Id: PII Removed
Timestamp: 2025-10-17T09:24:22.000Z
DPTI: PII Removed
Message: An unexpected error occurred.
Tag: 7q6ch
Code: 3221815318

I've logged with Microsoft as nothing I've tried works (repair, reinstall, rename of AppData folders and new mail profile).

Mike Fleet 0 Reputation points

2025-10-17T15:56:11.02+00:00

Microsoft rejected the reported issue, I don't want to have to raise a support case with them as it's normally outsourced support and not very helpful.

Answer 2

Hi @Arnel Valero,

Thank you for reaching out to the Microsoft Q&A Forum.
To help me narrow down why you’re seeing the “An unexpected error occurred” message with Tag: 7q6ch when trying to log in to Outlook and Microsoft Teams, could you please answer the questions below for me to gather more information about your issue?

Where are you signing in from? Is this happening on the desktop app, web browser, or mobile app?
Which operating system are you currently using? (Windows 10, Windows 11, MacOS, Android, iOS...)
Is this affecting multiple apps or just Outlook and Teams? Can you access other Microsoft 365 services like OneDrive or Word online?
Are you using a school or work account managed by your organization or a personal account (@hotmail, @gmail, @outlook.com,...)?
Is your account still licensed for Microsoft 365 services since missing or expired licenses can prevent app sign-in?
Do you see any additional error codes or prompts? Sometimes, the full error message includes extra details that can help pinpoint the cause.
Do you see this error immediately after entering your credentials, or during MFA verification?
Have you tried signing in via the web? Does the same error occur at Outlook or Teams for website?

Once I have a clearer understanding of your current situation, I’ll be happy to assist you with greater accuracy. Please feel free to share any additional details you believe are relevant. Screenshots are especially helpful and much appreciated.

Note: Please understand that our initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.

I hope this information is helpful. Please follow these steps and let me know if it works for you. If not, we can work together to resolve this.

Thank you for your patience and your understanding. If you have any questions, please feel free to reach out.

I'm looking forward to your reply.