[I use Software Version 2.1.0 Database Version 33]

When I put a valid HTML text into my own lesson such as



and then later try to edit this text the editing window renders html as any browser would do

Cannot provide an example because when I embed HTML text I get "invalid characters" message when I try to submit this bug report.

Thank you very much for this problem report. Indeed there is a bug and HTML tags are not interpreted a plain text. We will fix this bug in the next software release. Until then you can use the online version - there you can use HTML tags.

All the best from Berlin,
Your Tipp10 Team