I can’t play mp4 videos in Parole version 0.9.1 (codec missing), Xubuntu 16.04.6

I can’t fix Parole media player to play mp4 videos! I search and research on internet but none of suggestions worked for me. I installed latest version via Ubuntu repositories but no avail to play video, I got the following message :

“Required plugin could not be found”

“Parole Media Player requires to install plugins to play media files of the following type: H.264 (Main Profile) decoder”

Before upgrading to version 0.9.1 I had version 0.8.1, also not playing videos. What can I do to fix this? I have all dependencies installed (for parole, for gstreamer, and so on). Attached screenshot of parole. Thanks, Vladi Parole missing codec