Firefox opens with a transparent or blank window

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  • Creator: philipp
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On a system with malicious addons installed, Firefox may open with a blank or transparent window with no interface elements visible. In some instances the browser also crashes. This article describes how to resolve this problem.

blank or transparent window

Note: This is an example how an affected version of Firefox might look like.

1. Start Firefox in Safe Mode

Make sure that no other instance of Firefox is running or no other Firefox window is open.

You can then start Firefox in Safe Mode by holding down the shift key while starting Firefox or alternatively press the Windows key + R and open: firefox.exe -safe-modeholding down the option key while starting Firefox.

Safe Mode Fx 15 - Win

Now click on the Continue in Safe Mode button in order to run Firefox with extensions and themes disabled for this session.

2. Find and remove malicious extensions

  1. Click the menu button Fx89menuButton, click Add-ons and themesExtensions and themes and select Extensions.
  2. Look out for suspicious extensions like toolbars or entries that you have not installed on purpose (addons known to cause the problem are Codec 1.0, Codec M 6.0, Codec-C).
  3. Click the Remove button or in case it is not available disable those extensions.
  4. Afterwards restart the browser.
Note: If you're unsure which extension to remove or disable you can also press the Reset Firefox button when you start Firefox in Safe Mode. This will restore Firefox to its factory default state while saving your essential data. For more information see Refresh Firefox - reset add-ons and settings.

3. Check your computer for malware

After completing the above steps, check your computer for malware. See How do I get rid of malware? for some recommended malware removal programs.