Hello,

The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information.
Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!

Thank you.

This can be a problem with the font that is used to display the text.

You can do a font test to see if you can identify corrupted font(s).

• http://browserspy.dk/fonts-flash.php?detail=1

You can try different default fonts and temporarily disable website fonts to test the selected default font.

• Tools > Options > Content : Fonts & Colors > Advanced
• [ ] "Allow pages to choose their own fonts, instead of my selections above"

You can use this extension to see which fonts are used in text that is selected (right-click: "Show fonts in selection").

• fontinfo: https://addons.mozilla.org/firefox/addon/fontinfo/

You can use the System File Checker to check if font files are missing or corrupted.

Open a cmd.exe window as Administrator:

Start, click Programs, click Accessories, right-click Command Prompt, and choose Run as administrator.

After the cmd.exe prompt, type: sfc.exe /scannow

• http://www.sevenforums.com/tutorials/1538-sfc-scannow-command-system-file-checker.html