Uninstall and Re-install MS Teams
Click on the start menu
Type "Control Panel"
Open the control panel
Open Programs and Features
Remove all instances of Microsoft Teams
Try re-downloading and re-installing using this link
https://www.microsoft.com/en-gb/microsoft-teams/download-app
Delete Teams Cache
Sign out on Teams > Quit Microsoft Teams by right-clicking the icon and selecting Quit.
On your keyboard, Hold the Windows key, and press R
Cut and paste %appdata%\Microsoft\Teams in the RUN then OK.
Delete the contents of the entire folder.
Restart Device > Restart Microsoft Teams > Sign In.
