I can see the text of this troubleshooting just fine now. Could it be a problem with Java script? The pop up after I started asking the question was all jibberish.

This issue can be caused by the bitmap version of the Helvetica or Geneva font or another (bitmap) font that can't be displayed by Firefox in that font size. Firefox can't display that font in the specified size and displays gibberish instead. You can test that by zooming out (View > Zoom > Zoom Out, Ctrl -) to make the text smaller.

Uninstall (remove) all variants of that not working font to make Firefox use another font or find a True type version of that font that doesn't have the problem. ..... See http://kb.mozillazine.org/Issues_related_to_fonts#Gibberish

That fixed it for me! I had the same problem, and it was my Helvetica font that I recently installed from some random fonts website. Thanks for the help!