Bug 440242

SUMMARY
the /var/log/cron log file looks empty but its not
any system that runs logrotate will have four files
cron , cron.1 , cron.2 , cron.3 and cron.4
you should be able to select which one you want to look at too

STEPS TO REPRODUCE
1. click on the "Cron Log" button
2. at the bottom of the screen it says 18:20:23 Log successfully loaded


OBSERVED RESULT
3. you are looking at a blank screen now

EXPECTED RESULT
you should see the data in the cron log file


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 5.22.3
KDE Frameworks Version: 5.84.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION
4. as root on a terminal cd /var/log
5. cat cron 
6. you will get a screen full of information
also I could find no way to add other log files that are in my system
I'am running Slackware 15
log files in my sytem are debug , maillog , messages, faillog , lastlog ,secure, spooler, syslog.
most of these use logrotate so there are four versions of them