Korganizer doesn't understand http:// or file:// protocols. This means if I add a local calendar, it creates a folder "file:/" in my home folder instead of following /home/hussam/.local/.......ics Similarly, this breaks adding remote calendars. So instead of following http://www.kde.org/releaseschedule.ics, it adds a folder called http: in my home dir and inside it, a subfolder www.kde.org/releaseschedule.ics. The contents of the ics file won't show up in korganizer as well. Reproducible: Always
I can confirm this happens with korganizer 4.81 beta1 with kubuntu packages.
I traced this to the configuration of the akonadi_ical_resource. Manually editing ~/.config/akonadi_ical_resource_0rc removing the file:// part solves the issue for me for the local *.ics files. It seems that akonadi_ical_resource no longer knows how to speak url.
*** This bug has been marked as a duplicate of bug 352693 ***