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Installed Plug-ins

Shockwave Flash 16.0 r0 Shockwave Flash 12.0 r0

Having more than one version of a program may cause issues.

Grab the uninstaller from here: Uninstall Flash Player | Windows Uninstall Flash Player | Mac Then reinstall the latest version.

Flash Player Version 16.0.0.305
https://www.adobe.com/products/flashplayer/distribution3.html

I looked at the programs currently installed on my computer and I did have Flash Player Version 16.0.0.305.

But did try uninstalling and re-installing it. Now have version 17.0.0.134 installed - still mp3 files will not play from our site, these were working last week and do work when opened in google chrome but not when using Mozilla browser.

Please post a public link to the site, and a short list of bad files.

That would indicate that the files use a MP3 encoding that is not compatible with the HTML5 media player from your Firefox release.

Actually the current Flash for Windows is 17.0.0.134 Adobe Security Bulletin: https://helpx.adobe.com/security/products/flash-player/apsb15-05.html

Here is the link that was working a week ago: http://www.cranbrookalliancechurch.com/sermons/2015/February.php Click on any of the dates.

Now all mp3 links 2013-2015 not working, some from 2012 do work. On the plus side you are able to right click, save link and play from computer that way. Also only those using Firefox are having issues with the links.

I assume that this is because of the way the MP3 file is encoded.

Sample rate: 22050 Hz
Bitrate: 32 kb/s

If I open the file in a tab then I see a media player, but inspecting the page source shows a video tag with no source attribute, so Firefox seems to have a problem with decoding the media header despite the audio/mpeg content type. I don't know what to do about this apart from playing the file in an external player or play the file via an object or embed tag to make Firefox use a plugin.

Using a bookmarklet like this to force an audio tag doesn't work as well:

data:text/html,<audio src="%S" controls>

Thanks for looking into this, while the problem is not fixed the files will still play if downloaded, I just was not sure if this was an issue that Firefox was aware of:)

This thread might suggest that there is a problem with way the file is encoded because recoding the file works.

• [/questions/1052639] Existing (and validated) mp3s not playing since FF36

I do not have a program that can analyze the file header to see what is the difference. VLC shows the same codec information for both files in the other thread.

The video tag with no src attribute shows for both links, so that is likely not the problem, so it must be something else about the way the files got encoded.

The only bug that might be related to this I can find is this bug:

• bug 1140071 - mp3, no play but play when download it

If you can create a small sample file that shows the problem then you can attach it to this bug report as there is currently not much in the bug that developers can work with.

You could also try to find a regression range as this works in Firefox 35 and stops working in Firefox 36.

• https://github.com/harthur/mozregression

I have this problem too with some MP3 files on my site. I have a large number of MP3 files, all created in the same way using the same version of LAME. Some play back fine in Firefox (embedded with an <audio> tag or opening the URL directly in a tab), while others fail as described above. I can't see any difference in the filesize, ID3 tag, or encoding settings between the files which work and those which don't.

The problem files play back fine in other web browsers and media player software (including VLC, Quicktime Player and Quicktime Player 7) and they also work fine if I download the file and then drag it into a Firefox tab. But if I try to play directly from the remote URL in Firefox, I get the error "Video cannot be played because the file is corrupt" and the console log shows "Media resource <URL> could not be decoded".

What is particularly strange is that this problem is intermittent. If I force-refresh the URL several times, the error occurs about half the time, and otherwise the file plays back fine.

I have tested with Firefox 36 and 37.0.2 on Mac OS X. I have tried Safe Mode and resetting Firefox.

Here is an example of a file which works:

http://easyeartraining.com/example_works.mp3

and one which doesn't:

http://easyeartraining.com/example.mp3

This seems to be a combination of encoding (since it affects some files and not others) and network connection (since it doesn't happen every time)

Any help would be very much appreciated!

Update: I reported this in Bugzilla too and the issue has been confirmed by a contributor there:

https://bugzilla.mozilla.org/show_bug.cgi?id=949036