Google Translation:

Title: Invalid SSL certificate or non-secure connection
Hello community,
By today's maintenance work the previous faulty SSL certificate was exchanged.
So your browser now shows the TFA or the connection to TFA is secure.
However, if it is expected that your browser displays an unsafe connection or displays a security warning before entering TFA, we ask you to delete the cookies and then restart the browser, then the problem should be resolved.
greeting
Staff