Hi arrcher, which webcam is giving you that message?

Is your Firefox detected as able to play all formats listed on the following page, except perhaps the last one:

https://www.youtube.com/html5

If a site is generally known to work in Firefox, these are standard suggestions to try when it stops working normally:

Double-check content blockers: Firefox's Tracking Protection feature and extensions that counter ads and tracking may break websites that weren't built to operate normally without the blocked components.

Do you see a shield icon toward the left end of the address bar, near the lock icon? More info on managing the Tracking Protection feature in this article: What happened to Tracking Protection?.

Extensions such as Adblock Plus, Blur, Disconnect, Ghostery, NoScript, Privacy Badger, uBlock Origin or uMatrix should provide toolbar buttons to manage blocked content in a page. There may or may not be a number on the icon indicating the number of blocked items; you may need to click the button to see what's going on and test whether you need to make an exception for this site.

Cache and Cookies: When you have a problem with one particular site, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Clear Firefox's Cache

See: How to clear the Firefox cache

If you have a large hard drive, this might take a few minutes.

(2) Remove the site's cookies (save any pending work first). While viewing a page on the site, try either:

• right-click (on Mac Ctrl+click) a blank area of the page and choose View Page Info > Security > "Clear Cookies and Site Data"
• (menu bar) Tools > Page Info > Security > "Clear Cookies and Site Data"
• click the padlock or "i" icon in the address bar, then the ">" button, then More Information, and finally the "Clear Cookies and Site Data" button

In the dialog that opens, you will see one or more matches to the current address so you can remove the site's cookies individually without affecting other sites.

Then try reloading the page. Does that help?

Testing in Firefox's Safe Mode: In its Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox. (On Mac, hold down the option/alt key instead of the Shift key.)

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" Help > Restart with Add-ons Disabled
• (menu bar) Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

i am trying to view old faithful geyser webcam which I was able to until probably after Firefox update which is currently 63.0 (64-bit)

with add on's disabled getting error: hlsjs: Video file not found

with ad on's ENABLED getting error:hlsjs: Video file not found

works fine on the Brave browser no issues

im running windows 7 pro with up to date windows

https://www.nps.gov/yell/learn/photosmultimedia/webcams.htm

Did the HTML5 test page show support for all formats?

When I right-click the Old Faithful player, click This Frame, then Open Frame in New Tab, it opens:

https://www.nps.gov/yell/customcf/geyser_webcam_updated.htm

The source code of that page shows this URL for the actual video feed:

<source type="application/x-mpegurl" src="//56cf3370d8dd3.streamlock.net:1935/nps/faithful.stream/playlist.m3u8">

An m3u8 file is like a playlist: it indicates one or more file names to retrieve for the actual video. Those video chunks have a .ts extension, and my Firefox 63 on Windows 7 recognizes them as "mp2t" video files. So if H.264/MP4 is supported on the HTML5 test page, I think Firefox should be able to play these.

I'm not sure how hlsjs is involved. Hopefully someone with more video-savvy will be able to put this together.