error from cron job on cliupdate.php concerning libpng

by marteng69, Tuesday, December 04, 2018, 08:44 (2137 days ago) @ jtojnar

I would expect the libpng error to appear somewhere and you should be able to see what feed is causing it.

Unfortunately there is no error message in the debugging data.

Some additional information when the error occurs:
The cronjob runs four times every hour, every 15 minutes. The first time during the day it occurs is after 8 o'clock in the morning. Then it re-occurs almost every 45 minutes up to 11 o'clock in the evening. During the night, the cronjob runs all the time (what I can see in the logfile of the cronjob) but the error does not occur.