This error pop-up appears as if from nowhere, usually when a user is accessing a website with lots of media content. One Microsoft Answers user explained:
“It happens while using Firefox, Gmail, Facebook or logging into any Internet site. It pops up several times…when videos are loading on these pages…It does not do this when I access Pinterest.”
After doing clean reboots and restarting the program, the error will occur every few minutes and out of nowhere. There are a few ways that this error can be stopped, however. If method 1 doesn’t work, move on to method 2 – and if method 2 doesn’t work, move on to method 3.
Method 1: Remove the ffmpeg.exe File
To begin this method, head to System Restore by pressing Start, right clicking on Computer and choosing Properties. In the window that opens, find the System Protection tab, choose your Local Disk (usually C) and click Create.
You will be asked to enter a name for your restore point. You can name it anything you like, and then click Create. When the restore point has been created, you will be presented with a message that reads The restore point was created successfully. Press OK.
This creates a restore point that you can revert to if anything goes wrong when removing the ffmpeg.exe file.
Now, find Search in the Start menu and type in ffmpeg. A result should appear, which you need to right click and select open file location. This should open the file in Windows Explorer in a Mozilla folder. You will be unable to delete this file, but you will be able to move it. So that the Mozilla software stops referring to this file, drag it elsewhere – whether it’s your desktop, or anywhere else outside of the Mozilla folder.
Now, reboot your machine and begin using Mozilla again. The error should not continue.
Method 2: Reset Firefox
If removing the ffmpeg file yields no success, it is possible to reset Firefox in an attempt to stop this error. To do this, open Firefox and choose the menu button (which appears as three horizontal lines). Click Help and then select Troubleshooting Information.
If you can’t find the Help menu, you can access it by typing into the url bar about:support and pressing enter. This will take you straight to the Troubleshooting Information page.
In this page, you will see a module titled Give Firefox a tune up. Underneath this, there is a button labelled Refresh Firefox. Click it, and the browser will refresh itself. Once the process is complete, a window will appear. Click Finish.
This process saves information like bookmarks and passwords, but resets add-ons, themes and extensions and often solves the ffmpeg error.
Method 3: Uninstall and Install Latest Version
The final option is to uninstall Firefox and install the latest version of the software. To do this, press Start and then Control Panel. When the Control Panel window opens, click Programs. Then click Uninstall a program, which will take you to a page that lists all of your installed programs.
Find Mozilla Firefox, highlight it and then press Uninstall which will appear at the top of the list. You will be asked ‘Are you sure you want to uninstall Mozilla Firefox?’
Press Yes and the process will begin. Once complete, open a different browser (Internet Explorer is installed as standard) and go to https://www.mozilla.org/en-GB/firefox/new/ and press Free Download. Open the .exe file that appears in your Downloads folder (or wherever you have your downloads set to save to) and follow the on-screen instructions to re-install Firefox.