Here is "my story", I really hope you will be able to help me.
Some time ago, when I had Twitch stream in one of Firefox's tabs, my Firefox crashed and since that time I'm not able to use Firefox to view any Twitch streams nor Youtube live videos. All streams and videos work ok when I use external VLC media player to play them.
Twitch streams display "Your browser does not support playback of this video. (Error #6000)" message and when I'm opening https://www.youtube.com/html5 webpage I can see one red "!" near H.264 (the rest are all blue "ok" marks). This last webpage also says: "Firefox - H.264 playback depends on hardware and operating system support".
What I did try so far:
- I did reinstall my Firefox two times - first time it was with usage of "fresh start" option, second time it was full deinstallation-reinstallation with deleting all the data I was able to manually find on disk drive which was related to Mozilla/Firefox (including profiles). As of now I'm using Firefox Quantum 67.0.1.
- Browsing the web I noticed many posts like this one: https://www.reddit.com/r/Twitch/comments...r/dq5e2ny/ - to (re)install Media Feature Pack. I tried to use this: https://www.microsoft.com/en-US/download...x?id=16546 but it says: "This update is not applicable to your computer." - My OS is Windows 7 x64 Ultimate.
- In a last few days I found a few posts like this one: https://windowsforum.com/threads/where-c...dec.46515/ - so I installed your ADVANCED Codecs, but they did not help me either.
Do you have any other suggestion for me what I should do next? I would prefer to not reinstall my OS.
Thank you very much in advance for any help or guide.
Some time ago, when I had Twitch stream in one of Firefox's tabs, my Firefox crashed and since that time I'm not able to use Firefox to view any Twitch streams nor Youtube live videos. All streams and videos work ok when I use external VLC media player to play them.
Twitch streams display "Your browser does not support playback of this video. (Error #6000)" message and when I'm opening https://www.youtube.com/html5 webpage I can see one red "!" near H.264 (the rest are all blue "ok" marks). This last webpage also says: "Firefox - H.264 playback depends on hardware and operating system support".
What I did try so far:
- I did reinstall my Firefox two times - first time it was with usage of "fresh start" option, second time it was full deinstallation-reinstallation with deleting all the data I was able to manually find on disk drive which was related to Mozilla/Firefox (including profiles). As of now I'm using Firefox Quantum 67.0.1.
- Browsing the web I noticed many posts like this one: https://www.reddit.com/r/Twitch/comments...r/dq5e2ny/ - to (re)install Media Feature Pack. I tried to use this: https://www.microsoft.com/en-US/download...x?id=16546 but it says: "This update is not applicable to your computer." - My OS is Windows 7 x64 Ultimate.
- In a last few days I found a few posts like this one: https://windowsforum.com/threads/where-c...dec.46515/ - so I installed your ADVANCED Codecs, but they did not help me either.

Do you have any other suggestion for me what I should do next? I would prefer to not reinstall my OS.

Thank you very much in advance for any help or guide.