This worked in previous versions I have deleted all conf file from .local still the same result. Operating System: Debian GNU/Linux KDE Plasma Version: 5.17.5 KDE Frameworks Version: 5.70.0 Qt Version: 5.12.5 Kernel Version: 5.7.0-rc5-amd64 OS Type: 64-bit Processors: 4 × AMD Phenom(tm) II X4 10 Processor Memory: 7,8 GiB of RAM
It happened when upgraded from 19.08 to 20.04
That is intended. You should set a default calendar now. Go into the Calendar Manager (lower left area) and you'll see all the folders listed. pick the one you want as your default and click the rightmouse button to open the context menu. Select "Set as Default Calendar"