Hi there,
I send in in a bug report some time ago:
https://bugs.kde.org/show_bug.cgi?id=376540

Someone advised me to get more info about backtracing the bug, but I'm not quite sure how to get these infos... Can you help either with fixing the issue or getting more info about the crash itself?
Thanks indeed,
Johannes

First, I'd try to find the faulty executable's filename.
If You know it's the/a PIM-plugin for/in calendar, then
have a look if You find it in this list.

# Showing the list of running executables:
$ ps f -Aef | less -S

Then report back.

Another question:

What exactly is Your "crash"? What happens?

Does Your desktop freeze? Are You logged out?

How to find debugging packages to install:

# Only an example:

# KDE on Debian 9:
$ apt list '*dbg*' | grep pim
kdepimlibs-dbg/stable 4:4.14.10-7+b2 amd64

# On KDE Neon, try this:
$ apt list '*sym*' | grep pim


Find relevant '…-dbg' or '…-dbgsym' packages. Install it/them.
Then use gdb.