One of my team members is unable to connect to Teams Applications on Office 365, with this error message flashing on the screen – We’re sorry – we’ve run into an issue. Restart the process. Error code 6, to be precise. However, the same user is able to connect to Teams online without any errors. Can I get some walkthroughs for this?
Check the groups the user is part of with that of a user who can login without any issues.
Try to clean uninstall and delete all the Teams data and reinstall again see this can solve the issue.
Follow these steps to uninstall:
- Fully exit the Microsoft Teams desktop client. To do this, either right-click Teams from the Icon Tray and select ‘Quit’, or run Task Manager and fully kill the process.
- Go to File Explorer, and type in %appdata%\Microsoft\teams .
- Once in the directory, delete all files in this folder.
Login to teams (https://teams.microsoft.com/start) in the lift corner you will see an installer option download and install.
Please follow the below link