Every website I go to says the following: Error 408, that it's an encoding issue, and to install an addon for unicode.
Almost all of the text has been replaced with a question mark in a diamond. None of my other web browsers are having an issues (I'm using Chrome to write this.) For context, my computer was entirely fine, but then I went to read a book (while leaving it open) and windows must have done a restart for updates that it had been badgering me about last night, because some programs I'd had open before were closed. But Firefox had restarted nearly the same, except that when I went to open Twitter and Facebook both of them had the same Unicode issue.
The website also loads and displays normally for a moment before converting to this unicode error, which makes me wary about whether there is something different going on. It is, after all, trying to get me to install an addon.
Chosen solution
Looks like a malicious extension.
Try Firefox Safe Mode to see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes).
If Firefox is open, you can restart in Firefox Safe Mode from the Help menu:
- Click the menu button
, click Help 
and select Restart with Add-ons Disabled.
If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension. Please follow the steps in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause.
To exit Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.
When you figure out what's causing your issues, please let us know. It might help others with the same problem.
Read this answer in context 👍 0All Replies (11)
Type about:preferences#content<enter> in the address bar. Across from fonts and colors, press the Advanced button. On the bottom, turn on Allow Web Sites To Choose Their Own.
Fonts Information - Detected via Flash http://browserspy.dk/fonts-flash.php?detail=1
That was one of the first things I tried, but the box is already checked. I just tried unchecking and checking the box, but there was no change.
Chosen Solution
Looks like a malicious extension.
Try Firefox Safe Mode to see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes).
If Firefox is open, you can restart in Firefox Safe Mode from the Help menu:
- Click the menu button , click Help and select Restart with Add-ons Disabled.
If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension. Please follow the steps in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause.
To exit Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.
When you figure out what's causing your issues, please let us know. It might help others with the same problem.
Modified by TyDraniu
Hello robinsam155,
Error 408 : Request Timeout .....
You say that you're being asked to install an add-on for Unicode - could you please tell us where and how you are being asked to do that ?
I just noticed that my post has been marked as Chosen Solution - I don't think that was intenional ..... (?)
(you can rectify it by clicking on the 'Undo' button to the right)
The add-on download prompt was given at very website I visited. Using safe mode did make the problem stop though, so I've followed the instructions on troubleshooting I was given!
In the end, it seems that it was my gmail notification add-on was causing the issue, because disabling it but no other extensions stopped the issue. What I wonder now though is how this happened when the add-on was last updated on February 13th, and also if I should take any further steps to ensure my browser safety?
Also that was an accident, thank you! :) The mark solution button is much larger and greener than the reply one in my inbox.
robinsam155 said
The mark solution button is much larger and greener than the reply one
I wrote a bug report on this a long, long time ago. It was never acted on.
robinsam155 said
In the end, it seems that it was my gmail notification add-on was causing the issue
That was very good work. Well done. Please flag your https://support.mozilla.org/en-US/questions/1250773#answer-1198608 post as Solved Problem so others will know.
You should also contact Gmail about this.
Thank you for all your help!
You should also contact Gmail about this.
In what capacity would I do so? Also, it should be noted that after removing the extension I checked the add-on store (which is where I initially got it) and I don't see the extension there anymore, just many other similar ones.
robinsam155 said
it should be noted that after removing the extension I checked the add-on store (which is where I initially got it) and I don't see the extension there anymore, just many other similar ones.
That add-on must have been removed from addons.mozilla.org for a reason - and you had to find out the hard way what that reason was ...... :(
What I find weird though, is the fact that the add-on wasn't disabled in your addons manager ....
Oh well, problem is solved and all's well that ends well, eh ?
FredMcD said
Please flag your https://support.mozilla.org/en-US/questions/1250773#answer-1198608 post as Solved Problem so others will know.