dang. Well, im on regular 52.0 - I didnt go to 52.9 because I'm afraid it may completely kill the online web version of "slack" for me which I need. (i always have to use a firefox 60 user agent for that to load, and it works like only 75% of the time, sometimes have to refresh several times with the FF 60 user agent, for it to load)
So i dont currently use 52.9. Is that it, for youtube ?? I'll say by the way, i did follow all the instructions very carefully on this page a long time ago:
I did everything right, but there's only 1 single value i currently have disabled that does not ever seem to work properly. Which is "media.gmp.decoder.enabled"
If i set that to true, then youtube videos will try to load, but always stay in that spinning circle animation forever. Seriously. Doesnt matter if i click the seek bar a thousand times to any specific time on a video, it'll never get out of that loading animation, and it also completely breaks the "troubleshooting information" screen on firefox. for some reason all boxes won't be populated at all, until i set it to "disabled". I dont know what's up with that. :(