I'm have having real issues trying to play mp4 videos from Online video plugin. I have attached the error zip file for your reference. Been trying for the last 4 days to figure it out. Help would be appreciated.
such problems can often be a codec problem.
try uninstall onlinevideos and install the latest version.
then install saf-codecs as unlocked SAF-installation! and follow the instructions: https://forum.team-mediaportal.com/threads/saf-v6-based-on-lavf.95635/
select the power-dvd-codecs for h.264 and also for all others.
this codecs pack is really good work from its dev and should playback every format.