Teams Microsoft login issue

Hi @GM47,

Please understand that our forum is a public platform, and we will modify your question to cover your personal information including your organization domain name in the description. Please notice to hide these personal or organization information next time you post error or some information to protect personal data.    

I have moved the information to the Private message if you need to add any more privacy information please add it in there.

Regarding your issue, may I kindly ask a few questions to help understand it better: 

• I saw that you posted your question under the Business category so to better support you, would you mind letting me know is this account a personal Microsoft account (Outlook.com, Hotmail, Live) or a work/school account provided by an organization?  
• Does this happen on Wi‑Fi, mobile data, or both? 
• Can you sign in to Teams on a desktop or web with the same account? 
• Are you receiving MFA prompts, or none at all? 
• Can you sign in to other Microsoft apps on the same phone? 
• Did anything change about 1 week ago (OS update, MFA, device change)? 

Hope to hear back from you soon.  

The initial response may not fully address your needs, but it will help me better understand your situation. Once I get the information, I will try my best to find the next steps. 

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The error indicates a generic sign-in failure in Microsoft Teams on a mobile device. Based on similar reported issues, use these steps:

1. Fully remove and reinstall the apps
   • Uninstall both Microsoft Teams and Microsoft Outlook from the phone.
   • Restart the phone.
   • Reinstall Teams (and Outlook if used) from the official app store.
   • Try signing in again.
2. Check for temporary service or tenant issues
   • Similar errors have been resolved simply by waiting and trying again later. If this is a service-side or tenant access issue, it may clear after some time.
3. If the issue persists
   • Since the error is “unexpected” and tied to a correlation ID, contact the organization’s IT admin or Microsoft 365 admin.
   • Provide them with the full error details (Correlation Id, Timestamp, Code). They can check tenant status and, if needed, open a support request with Microsoft and include these details.

If this is happening only on mobile and not on desktop/web, emphasize that in the support request, as it can help narrow down whether it is a client-specific issue.

References:

• Restore your access to Microsoft Teams
• Resolve sign-in errors in Teams
• Why am I having trouble signing in to Microsoft Teams?
• Teams app on Android crashes right after opening - Microsoft Q&A
• An unexpected error occurred. Tag: 4oggx Code: 1864098253 - Microsoft Q&A
• Tried loggin into Teams and Outlook and got this message on outlook, and unable to log into teams. - Microsoft Q&A