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.''' You can check for corrupted and duplicate fonts and other font issues: http://www.thexlab.com/faqs/multipleappsquit.html - Font Book 2.0 Help: Checking for damaged fonts http://www.creativetechs.com/iq/garbled_fonts_troubleshooting_guide.html ------------------------ '''[https://addons.mozilla.org/en-US/firefox/addon/nosquint/ NoSquint]''' {web link} NoSquint allows you to adjust the text-only and full-page (both text and images) zoom levels as well as color settings both globally (for all sites) and per site.

Firefox 41 will allow icon fonts to work with the font setting in "Options/Preferences > Content > Colors" disabled. *http://www.ghacks.net/2015/07/21/firefox-41-mozilla-modifies-how-icon-fonts-are-handled-by-the-browser/ You can set <b>gfx.downloadable_fonts.enabled</b> on the <b>about:config</b> page to false to disable downloadable fonts.