Greetings,

Up until a few days ago, I've been able to watch all Youtube videos, but now for many recently created videos I get this error message:
"Your browser does not currently recognize any of the video formats available".

It gives a link to a FAQ about HTML5 video, which when I go to it, it seems to assess my browser in real-time and has determined that my K-meleon browser supports: HTMLVideoElement, Media Source Extensions, and WebM VP8. However, it does not support: H.264, MSE & H.264, or MSE & WebM VP9.

I looked up which version of K-Meleon I'm using (clicking "About K-Meleon"), and it says:
Mozilla/5.0 (Windows NT 6.2; WOW64; rv:38.0) Gecko/20100101 Firefox/38.0 K-Meleon/76.0

My computer is Asus All-in-One running Windows 10.

Anyway, if anyone has any insights on this, I would be very grateful! Thank-you in advance.

Yeah youtube is at it again, there have been a couple reports in other forums too
But you say you have win10, at any rate younger as XP, so you should get H264. Perhaps you have this pref blocked?

https://msfn.org/board/topic/175591-enable-mp4-h264-aac-html5-video-in-firefox-on-windows-xp-without-flash/?page=21

Quote
VistaLover
by toggling media.windows-media-foundation.enabled (from true to false) I simulated an XP environment and conducted tests before posting this...
On those of us on Vista and higher, Fx 28.0 by default has H.264 ticked in blue, because Fx 28.0 has support for Media Foundation, hence it has access to patented system decoders (h.264/aac) not present in the XP OS (by a M$ decision)... So I can still use Fx 28.0 on Vista on youtube, they serve me a progressive download (no MSE) of an MP4 encode...

And guess the "mediasource" prefs too.

People on much older systems can only download the videos, either on websites like qdownloader.net, or using scripts like this:
http://kmeleonbrowser.org/forum/read.php?9,142050

Quote
torbetron
Mozilla/5.0 (Windows NT 6.2; WOW64; rv:38.0) Gecko/20100101 Firefox/38.0 K-Meleon/76.0
My computer is Asus All-in-One running Windows 10.

That's contradictive Windows NT 6.2 is Window8 not 10.
Must be a faked UA.

Thank-you, Siria, for all those suggestions. I looked at my config file, and I changed from false to true the following line:
media.mediasource.webm.enabled

That seems to have done the trick (youtube videos that previously did not play are now playing).

The user agent is what it is by default. I read in this forum that there's an extension I can add that gives me custom user agent capability. I'll try installing that, too.

I have similar problem.
I'm using KM 76 RC1 on W10 and youtube working fine.
When I copied it to Windows Thin PC (based on W7) youtube stop working...
I check this site https://www.youtube.com/html5 and it says:
H.264, MSE & H.264, MSE & WebM VP9 missing but on W10 missing nothing.
KMG working fine on both systems but I need 76 RC1 also.
So, W7 or Windows Thin PC need some codecs or what ?

EDIT (Fixed):
https://www.reddit.com/r/firefox/comments/6s78fd/youtube_says_your_browser_does_not_currently/

media.mediasource.enabled
media.mediasource.webm.enabled
media.mediasource.mp4.enabled

__________________________________________
How to install Firefox addons in KM 76 RC:
http://kmeleonbrowser.org/forum/read.php?9,141979
Icons for Goanna KM/SM:
http://kmeleonbrowser.org/forum/read.php?10,150634
K-Meleon Quick Reference:
http://kmeleonbrowser.org/docs.php
Basilisk/KM/SM xpi converter:
https://www.addonconverter.fotokraina.com/
Best regards.



Edited 1 time(s). Last edit at 10/14/2018 10:12AM by luk3Z.

( _howto_ about:config)

Quote
luk3Z
media.mediasource.enabled
media.mediasource.webm.enabled
media.mediasource.mp4.enabled

Yep, and I think the first one is the main switch for all mediasource subtypes.

============ General / howto tip ===========

How to use "about:config"
Just as occasional hint for any future readers who may be interested or not fully aware yet.
This is by far the easiest way to discover, check, toggle or test over thousand hidden prefs:
Just type that adress into the urlbar and open it (or menu Edit > Configuration > Browser Configuration)

In the filter line type what you're looking for. In this case "media" (=most video/audio settings)
Now look around the search results which of the countless prefs sound interesting, then toggle or modify them with double-click. Some of them will work instantly, some others need a browser restart to become active.

IMPORTANT!!
If not 100% sure what you're doing, make a backup copy of file "prefs.js" first!
It's in the current profile folder (menu Edit > Configuration > Profile Directory)
That's were all your changes in "about:config" will be stored automatically too.
But also deleted automatically if the new value now matches the browser's default value!

But having a backup copy of prefs.js, it's safe enough to experiment freely with all prefs in about:config, no danger. If anything goes wrong, simply close the browser and replace prefs.js with the backup file again

More details here:
http://kmeleonbrowser.org/forum/read.php?1,148008

Yes...I know - nobody wants to talks with me about XP SP2 anymore - but it does all I need & nothing that I don't, very nicely inside a VM, so:
I enabled those settings & videos I tested recently that refused to play...now do.

Here's the strangeness=> some with everything, some without sound, some with sound, but black screen only.

Any clues of how to fix this (without changing my OS...) ??

Thanks for any helpful replies.

I think there is no way with KM-Gecko and XPSP2. Well, I have the same issue with KM75.1 even under Win7, for example.

And it seems that KM 76 Pro under XPSP3 plays all well. May be you give some links with no sound or no picture?



Edited 3 time(s). Last edit at 10/27/2018 08:24PM by rodocop.

Hi Rodocop - good to see you !!
I'm very interested in Roytam's 74G version as mentioned in the bottom 3 replies here:
http://kmeleonbrowser.org/forum/read.php?19,145119

I tried a bunch of videos with very assorted results & have no record of which did what, but when I try a few more I'll do better at it & try to report back here.

Meantime - my oddest thing is a more recent version of the Mypal browser does a really good job with YT videos - but is very laggy about doing most everything else.

The slightly older version of Mypal that I use daily is as quick & light as K-Meleon, but still not as nice to use.

Thanks, and Best Wishes.

smallhagrid