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How do I fix "content encoding error"

  • 8 replies
  • 24 have this problem
  • 750 views
  • Last reply by wernerfr

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Many sites (mozilla included) no give me the above error message - now working with other browsers and am disappointed that after searching the web all over there seem many people with similar problem but no solution.

Many sites (mozilla included) no give me the above error message - now working with other browsers and am disappointed that after searching the web all over there seem many people with similar problem but no solution.

Chosen solution

Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.

You may still have to clear the cache.

If clearing the cache doesn't work the try to delete the cache folder manually on the hard drive.

  • C:\Users\<user>\AppData\Local\Mozilla\Firefox\Profiles\<profile>\

The "Application Data" folder in XP/Win2K and the "AppData" folder in Windows Vista and later Windows 7+ versions are hidden folders.

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All Replies (8)

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You can check the network.http.* prefs on the about:config page.

Reset network.http prefs to the default value via the right-click context menu -> Reset if they are user set (bold).

Check at least:


Reload web page(s) and bypass the cache to refresh possibly outdated or corrupted files.

  • Press and hold Shift and left-click the Reload button.
  • Press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
  • Press "Command + Shift + R" (MAC)

Clear the cache and the cookies from sites that cause problems.

"Clear the Cache":

  • Tools > Options > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

  • Tools > Options > Privacy > Cookies: "Show Cookies"
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Unfortunately it did not work ... still same problem. Have done all of above, un and reinstalled firefox, created now prefs.js (or more accurately renamed prefs.js prefs.old).... Guess I have to switch to different browser.

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Which security software (firewall, anti-virus) do you have?

A possible cause is security software (firewall,anti-virus) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.

See:

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Thank you core-el for trying to help... I really appreciate it.

I use Kaspersky and have done as asked but still no joy. If I uninstall firefox completely and reinstall would that work. Really tempted to switch to other browser but I AM so used to firefox... Thanks again

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Chosen Solution

Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.

You may still have to clear the cache.

If clearing the cache doesn't work the try to delete the cache folder manually on the hard drive.

  • C:\Users\<user>\AppData\Local\Mozilla\Firefox\Profiles\<profile>\

The "Application Data" folder in XP/Win2K and the "AppData" folder in Windows Vista and later Windows 7+ versions are hidden folders.

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Thank you, cor-el!!!' I got it working. Cleared cache as you said but did not work - then in safe mode error was not encountered at all - all sites started normally. While in safe mode I renamed prefs.js file, cleared cache and deleted cookies. Oh I also uninstalled weather network as it did not start up correctly. - I know I should have done one thing at a time to see which solution helped but I had spent a lot of time on this already so opted for major sugeryThen on restart in "normal" mode sites came up without error. Thanks again for your patience and help. Have a great New Year!

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You're welcome.

Thanks for reporting which steps have helped you to fix this as it may help others.

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Hello cor-el. Found the culprit. This morning got error again as on restart a recent addition "SpeedBit Accelerator" started up again. Switched that program off and error disappeared. So all that work when all it needed was that one program not running! Happy New Year