How to Fix: MEDIA_ERR_UNKNOWN Chrome, Firefox, Etc

Dennis Faas's picture

Infopackets Reader Gina V. writes:

" Dear Dennis,

I watch a lot of sermons from my church online, but since around October this year I keep getting 'An unanticipated problem was encountered, check back soon and try again. Error code: MEDIA_ERR_UNKNOWN' I don't understand what this means. I have searched Google and it seems a lot of people have the MEDIA_ERR_UNKNOWN Chrome error message when playing videos in the web browser. I also have a MEDIA_ERR_UNKNOWN Firefox error. I'm not sure what to do next. Can you please help? "

My response:

Generally speaking, the 'MEDIA_ERR_UNKNOWN' is a generic error message, and usually (but not always) means that a web browser plugin required to play the video is not installed or has been disabled, or there is a problem with the web browser itself.

How to Fix: MEDIA_ERR_UNKNOWN Chrome, Firefox, Etc

There are three ways to fix this problem - with a very important caveat near the end:

  1. Try playing the video in another web browser. If the problem is with your favorite web browser, then playing it with another browser may be a temporary workaround. For example, if it doesn't play in Firefox, try Chrome. If it doesn't work in Chrome, try Internet Explorer or Edge.
  2. If the video works in another web browser but still won't work in your favorite browser and you insist on using your favorite web browser to play the video: uninstall and reinstall your favorite web browser, then try playing the video again. If it still doesn't work, you are welcome to contact me for 1-on-1 support (also described near the end of the article).
  3. Yet another option is to view the source code of the web page to figure out what video technology is being used. This will help you understand what the 'MEDIA_ERR_UNKNOWN' error message is in reference to (most of the time).

    To do so:

    First, copy a snippet of web page text near the video in question. You will search for this text snippet in the source code of the web page (described further down) to help you determine which video technology being used, which is likely the root cause of your MEDIA_ERR_UNKNOWN error.

    To view the source code, do one of the following:

    For Chrome or Firefox: right click on the web page in question and select "View Page Source".

    For Internet Explorer, right click on the web page and select "View Page Source".

    For Edge: click the three horizontal dots near the top right of the screen -> More tools, then select "Developer Tools", then click "OK". Now you can right click the web page and select "View Source".

    Once the source is available, press CTRL-F to open the search box, then press CTRL-V to paste the text snippet you copied earlier. Scroll through the source on the next few lines and look for an embedded object. For example, you might see <object type="application/x-shockwave-flash"> in the source code, which is indicative that the webpage is using Adobe Flash to play video content. Or, you may see <video> which means it is HTML5 video.

If the video is HTML5, then most likely it is a browser issue since all major web browsers support HTML5 now. If the video is in fact using Flash, then it is most likely being disabled by the web browser. Read on for more detail as this is a very important caveat.

Major Caveat - Most Web Browsers Abandon Adobe Flash Videos as of September, 2019

Adobe Flash was one of the first technologies to develop multimedia and interactive video for web pages. Unfortunately, Adobe Flash is also one of the worst offenders for having security issues. In 2015, Adobe Flash was the #1 security threat.

As of September 2019, most major web browsers (including Chrome and Firefox) have disabled Adobe Flash / Shockwave videos by default. What this means is that videos on web pages which worked previously may no longer work, and will instead display the MEDIA_ERR_UNKNOWN error message. In October, 2019, Google stated it will no longer index web pages that have flash content.

That said: both Internet Explorer and Microsoft Edge will support Adobe Flash until the end of 2020. However, due to the security threat it is not recommended; instead, search Youtube for a similar video, if possible. All Youtube videos are encoded using HTML5, which is the secure and the successor to Adobe Flash.

If the Flash video you're trying to play isn't available in another format elsewhere (Youtube), then there is little you can do to get around this problem - other than to perhaps email the webmaster and ask if he or she would be willing to convert the content to HTML5.

I hope that helps.

Additional 1-on-1 Support: From Dennis

If all of this is over your head, or if you still have the MEDIA_ERR_UNKNOWN in your web browser and aren't sure how to proceed, I can help using my remote desktop support service. Simply contact me, briefly describing the issue and I will get back to you as soon as possible.

Got a Computer Question or Problem? Ask Dennis!

I need more computer questions. If you have a computer question - or even a computer problem that needs fixing - please email me with your question so that I can write more articles like this one. I can't promise I'll respond to all the messages I receive (depending on the volume), but I'll do my best.

About the author: Dennis Faas

is the owner and operator of With over 30 years of computing experience, Dennis' areas of expertise are a broad range and include PC hardware, Microsoft Windows, Linux, network administration, and virtualization. Dennis holds a Bachelors degree in Computer Science (1999) and has authored 6 books on the topics of MS Windows and PC Security. If you like the advice you received on this page, please up-vote / Like this page and share it with friends. For technical support inquiries, Dennis can be reached via Live chat online this site using the Zopim Chat service (currently located at the bottom left of the screen); optionally, you can contact Dennis through the website contact form.

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