This can be caused by corrupted cookies or cookies that are blocked (check the permissions on the about:permissions page).

• https://support.mozilla.org/kb/fix-login-issues-on-websites-require-passwords

Clear the cache and cookies only from websites that cause problems.

"Clear the Cache":

• Firefox/Tools > Options > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

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

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

• Do NOT click the Reset button on the Safe Mode start window.

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

First , I cleared the cache as advised to no avail. Then I tried to remove cookies but found the steps a little different to get there. You have to make custom settings to get the cookies to show. But clearing them did not help. The only part of this response that corrected the issue was to restart in Safe Mode. I then went to the "extensions" and disabled them (5) one at a time and then went back to the issue but each time it was the same. In checking the themes, I only had the DEFAULT. Something about the Safe Mode fixed the problem but I don't know what it was. Any other thoughts appreciated.

You can inspect the cookies for the domain in the currently selected tab via these steps:

• Click the "Site Identity Button" (globe/padlock) on the location bar
• Click "More Information" to open "Page Info > Security"

• Click "View Cookies" to view the cookies for the domain in the currently selected tab

I'm not seeing any extension in your System Details List that would effect cookies

That would only leave an issue with the JavaScript JIT compiler and would mean that some JavaScript runs on that page or in an extension that doesn't work well.

That would involve to toggle some prefs on the about:config page.

1. you can open the about:config page via the location bar
2. paste javascript.options.*jit in the Search bar at the top of the about:config page
3. double-click the javascript.options.baselinejit.chrome and javascript.options.baselinejit.content prefs to toggle their value to false

See also http://kb.mozillazine.org/about:config

In Firefox Safe mode these changes are effective:

• all extensions are disabled (about:addons)
• default theme is used (no persona)
• userChrome.css and userContent.css are ignored (chrome folder)
• default toolbar layout is used (file: localstore-safe.rdf)
• Javascript JIT compilers are disabled (prefs: javascript.options.*jit)
• hardware acceleration is disabled (Options > Advanced > General)

• plugins are not affected
• preferences are not affected

You can remove all data stored in Firefox from a specific domain via "Forget About This Site" in the right-click context menu of an history entry ("History > Show All History" or "View > Sidebar > History") or via the about:permissions page.

Using "Forget About This Site" will remove all data stored in Firefox from that domain like bookmarks, cookies, passwords, cache, history, and exceptions, so be cautious and if you have a password or other data from that domain that you do not want to lose then make a note of those passwords and bookmarks.

You can't recover from this 'forget' unless you have a backup of the involved files.

It doesn't have any lasting effect, so if you revisit such a 'forgotten' website then data from that website will be saved once again.

Still no results. I have tried all your steps manually with the exception of the userChrome.css and userContent.css files. Reality is that it works fine in Safe Mode every time. I haven't tried to reload the latest version yet. Would that make any difference? Thanks for your help