Hi Hans Dieter,
Development are aware of the IE11 EOL and we have a story on the backlog to fix the error you are seeing and change a number of internal API calls over to the new Edge ones (or remove them completely).
From Microsoft:
Internet Explorer is a component of the Windows operating system (OS) and follows the Lifecycle Policy for the product on which it is installed and supported.
Please note that the Internet Explorer (IE) 11 desktop application will end support for certain operating systems starting June 15, 2022.
Some versions of Internet Explorer may be supported past the latest Windows OS end date when Extended Security Updates (ESUs) are available. Go here for a list of products offering ESUs.
So its only the oldest OS Versions that are ending IE11 Support next year along with the OS its self.
Rgds,
Steve