Microsoft Teams – The application database has been wiped. this tab must be refreshed or be closed

Today when i logged into my development tenant’s teams I got the following message:

The application database has been wiped. this tab must be refreshed or be closed

This looks scary. Well I only have one button to click. After a login i got to the following:

I’ve not noticed anything missing but the warning given doesn’t make me comfortable.

So what caused this error message. It took me a few weeks before I reproduced the error.

The following steps will cause this error:

• Open Microsoft Teams in your browser.
• Open Microsoft Teams in another tab.
• Log out of Microsoft Teams in one tab, the other tab now gives the error.