It is not a software problem but a hardware problem. My computer detects the S820D as an S820 because I changed the settings in the printer's service menu.
When trying to reset my waste ink counter it seems I unfortunately set my Canon S820D to an S820.
Now the printer does not work any longer. :(
How can I reset the printer model type from S820 to S820D now?
Thank you very much for your assistance!