Something in Firefox is blocking viewing. It happens while in Yahoo/Yahoo Mail, while trying to view Firefox personas/themes and with other sites.

Question

(for example, in Yahoo mail I am unable to see the box to click to make an email read or unread. In looking at firefox personas all I see are white boxes where I should see personas.) I have uninstalled Firefox three different times to no avail. I can go into Opera and I can see things normal. I would appreciate any help.

Answer 1

Make sure that you allow pages to choose their colors and that you haven't enabled High Contrast in the Accessibility settings.
*Tools > Options > Content : Fonts & Colors > Colors : [X] "Allow pages to choose their own colors, instead of my selections above"
*https://support.mozilla.org/kb/Changing+fonts+and+colors
*http://kb.mozillazine.org/Website_colors_are_wrong
If images are missing then check that you aren't blocking images from some domains.
*http://kb.mozillazine.org/Images_or_animations_do_not_load
You can try to clear the cookies.sqlite file(s) to reset all cookies if clearing cookies didn't help.
Try to create a new profile as a test to check if your current profile is causing the problems.
See "Basic Troubleshooting: Make a new profile":
*https://support.mozilla.org/kb/Basic+Troubleshooting#w_8-make-a-new-profile
There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins" in case there are still problems.
If the new profile works then you can transfer some files from the old profile to that new profile, but be careful not to copy corrupted files.
See:
*http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox