Hello,
I have been using KDE-Kontact/Korganizer for years and have always been reasonably happy with it. Now, after installing Mint 18/KDE with Plasma 5.6. a couple of weeks ago I find that Korganizer has some serious shortcomings. E.g., it crashes with a SEGFAULT every time I try to add a new calendar event. I have followed the procedure about sending debugging info. Additionally, it does not remember the colours for various categories of event items. Has anybody experienced these issues? Basically, to me Korganizer is not usable in this state. Thanks for any hints...