Hi @IBN ,
Please have a look at the lower left corner of error message screen and see if there's any error code which might be helpful for further analysis.
Besides, below are some troubleshooting steps you could try and see it can help:
- Log in to Teams web client via teams.microsoft.com and check the result.
- Remove the Teams cache and then reinstall the Teams client. For instructions about how to clear the Teams cache, you may refer to this link. To reinstall Teams, you can uninstall it via Control Panel, then download and install it via https://aka.ms/getteams.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.