SUMMARY


STEPS TO REPRODUCE
1. Start apper and select "Updates"
2. Have something selected to update, but not all packages shown updatable
3. Press the update button

OBSERVED RESULT
The packages are downloaded and updates done, and after that apper shows the circle for waiting and then crashes.

EXPECTED RESULT
Return to the list of remaining updates instead of crashing


SOFTWARE/OS VERSIONS
Windows: 
MacOS: 
Linux/KDE Plasma: Fedora 29 (or 28)
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
I first discovered this when I had upgraded my system from Fedora 27 to Fedora 28 in May, and it still persist after all the package updates during Fedora 28 and upgrading to Fedora 29.
If I start apper from Konsole, it shows several rows of "kf5.kwidgetsaddons: Invalid pixmap specified." during the process, and finally
KCrash: Application 'apper' crashing...
KCrash: Attempting to start /usr/libexec/drkonqi from kdeinit

I reported this to Fedora bugzilla ( https://bugzilla.redhat.com/show_bug.cgi?id=1615818 ) in August, and when I reported that it still happens after upgrading to F29, they replied that I should report it here.