User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Firefox/91.0

Steps to reproduce:

Clicking on any netflix content should start playing the content but it doesn't on Firefox.

Actual results:

Cannot play any netflix content on firefox.

Expected results:

When you're open any netflix content it should be playable on a browser but it's not in Firefox.

The Bugbug bot thinks this bug should belong to the 'Core::Audio/Video: Playback' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Does this work in you use a recent version of Firefox?

Does not work in recent version of Firefox. (99.0)

(In reply to Bryce Seager van Dyk [:bryce] (he/him) from comment #3)

Does this work in you use a recent version of Firefox?

Does not work in recent version of Firefox. (99.0)

Can you navigate to about:support and copy the information there using one of the buttons provided, then paste that information onto this bug, please?

Am I reading the support information correctly that you're running on Darwin 17.7.0 but running with a spoofed UA?

(In reply to Bryce Seager van Dyk [:bryce] (he/him) from comment #10)

Am I reading the support information correctly that you're running on Darwin 17.7.0 but running with a spoofed UA?

I'm running on MacOS High Sierra 10.13.6

Does this work if you try with a fresh profile?

(In reply to Bryce Seager van Dyk [:bryce] (he/him) from comment #12)

Does this work if you try with a fresh profile?

Yep it's worked. What's the issue?

It could be addons, I'd investigate there first. You could try disabling them all, and if that works, re-enabling them until you find the one causing the issue.

Having your user agent showing a different OS than you're on can lead to compat issues with sites like Netflix when they try and start encrypted video playback, so it may be worth investigating that (this could also be addon related).

Private browsing is also known to interfere with Netflix, so if something is forcing windows into private browsing mode, that can trip up Netflix.

(In reply to Bryce Seager van Dyk [:bryce] (he/him) from comment #14)

It could be addons, I'd investigate there first. You could try disabling them all, and if that works, re-enabling them until you find the one causing the issue.

Having your user agent showing a different OS than you're on can lead to compat issues with sites like Netflix when they try and start encrypted video playback, so it may be worth investigating that (this could also be addon related).

Private browsing is also known to interfere with Netflix, so if something is forcing windows into private browsing mode, that can trip up Netflix.

I get it. This issue because of addons. But i using same addons in google chrome it's working really well how?

I can reproduce this issue on both Windows 10 and 11. But the weird thing is that, this only happens on my local build. On the official Nightly, this issue never happens. I pretty sure this is a regression, but I can't use moz-regression to find out the culprit, because this issue just doesn't appear on the official build.

In addition, I can use my local build to play Widevine video on Shaka Player, but on Netflix I would always get F7121-1331 no matter what profile I was using. I wanted to try if the private browsing window works, but the private window would always get closed automatically when I navigated to Netflix, not sure if that was a crash or something.

I was debugging this yesterday, and found that Widevine seems not being able to write (or read?) file in the disk. I saw a failure on this part. fileLength is always zero.

--

[update] maybe this is not the root cause. I checked the folder of the default profile for my Nightly, there is a file under ....\srx4d0hc.default-nightly-1675197608365\gmp\WINNT_x86_64-msvc\gmp-widevinecdm\storage which is also 0KB. So I guess the fileLength would also be zero for Nightly.

Possibly a dupe of Bug 1763978 - Widevine DRM breaks when using a non-default profile folder in 99.0 Windows-x64

I've tried the patch from bug 1763978, but sadly it didn't work :(