Start Firefox in Use Troubleshoot Mode in Firefox 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.org/kb/Safe+Mode

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Thanks for the note. It had a lot of useful information.

Alas, the first time I restarted Firefox with in Safe Mode, I was able to see a "View Source" page. I then disabled all the add ons. The "View Source" worked once. I reloaded the default settings and themes. The "View Source" no longer works in Safe Mode or regular mode.

What's happening now?

Does it work if you uninstall Firebug?

See also:

• http://kb.mozillazine.org/Corrupt_localstore.rdf
• https://support.mozilla.org/kb/Toolbar+keeps+resetting

Nope - {;-(

Actually, none of the windows in FireFox open for example: download - just flashes.

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