i'm running ubuntu 16.04
timetrex version v9.1.3 - manual
apache2 - 2.4.18
i was also just having an issue where a log file wasn't readable i have fix that issue.
i'm not sure what i need to start or how to do it to get the service running right to get rid of this message.
i also looked at others posts about this issue trying command su cs -c "php /var/www/html/timetrex/maint/cron.php" > /dev/null 2>&1 and did nothing also tried it using www-data but that didnt work. owner of the timetrex files are root apache2 is running under www-data