Reset the page zoom on pages that cause problems: View > Zoom > Reset (Ctrl+0 (zero); Cmd+0 on Mac)

• http://kb.mozillazine.org/Zoom_text_of_web_pages

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

"Clear the Cache":

• Tools > Options > Advanced > Network > Offline Storage (Cache): "Clear Now"

"Remove Cookies" from sites causing problems:

• Tools > Options > Privacy > Cookies: "Show Cookies"

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.com/kb/Safe+Mode

I can view attachments within my Yahoo emails using IE and Google Chrome, but not Firefox. Even when I click on that attachments to view them - I get the same thing - nothing.

You don't have to disable any addons or extentions!!!You guys are not going to believe this I figured out the problem it's really dumb...ok here goes the attachment uploader loads seperate so I got to thinking it's a popup so I went to options content and under block pop ups there is an option exceptions click on that and in the box type firefox.com and hit allow pow its fixed!!!!! :-)