What changes do you do before this issue happened?
Does anyone else have the same issue?
You could troubleshoot this issue from the following several methods:
- Check if the date and time zone are set correctly.
- Check if TCP 443 and UDP 3478-3481 ports are opened in your firewall.
- [Perform a clean boot][2] to exclude the conflict with other applications.
- Make sure your Teams client is the latest version.
If many people experience the same issue, please contact IT admin to check if there is any error message of Microsoft Teams health status in Microsoft 365 admin center > Health > Service health.
If the response is helpful, please click "Accept Answer" and upvote it.
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