okular 4:17.12.2-2.1 on amd64 also had problems after being prelinked recently:
KCrash: crashing... crashRecursionCounter = 2 KCrash: Application Name = okular path = /usr/bin pid = 11571 KCrash: Arguments: /usr/bin/okular ZH Toolbox Pack_Dec18.pdf KCrash: Attempting to start /usr/lib/x86_64-linux-gnu/libexec/drkonqi from kdein it sock_file=/run/user/1000/kdeinit5__0 QSocketNotifier: Invalid socket 8 and type 'Read', disabling...QSocketNotifier: Invalid socket 11 and type 'Read', disabling...QSocketNotifier: Invalid socket 10 and type 'Read', disabling... Reinstalling okular and excluding it from prelinking solved the problem. prelink is version 0.0.20131005-1 Arthur.
