Hi, it's computer code, what can I say stuff breaks or goes corrupted. Less used things like explorer do not.

Please try 7min fix : uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files , C:\Program Files(x86) & C:\ProgramData Then restart system. Then run Windows Disk Cleanup. (Note: This should be Pinned and run Weekly, If never done below expect 10's of gig's) Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do :

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer

Reinstall with Current Release Firefox 59.0.1 with a Full Version Installer

• https://www.mozilla.org/firefox/all/

If still having issues please turn on Cleartype font rendering within your windows settings.

Make a new Profile and TEST : https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles if it is the profile can help you move non-corrupted stuff over to it.

Please let us know if this solved your issue or if need further assistance.

Make sure you are not blocking content.

Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

Thanks both for your suggestions. i do not have the computer skills to uninstall a browser with multiple tabs operating and many bookmarks and reinstall it in safety and in confidence. We should have the latest Firefox, it is supposed to update automatically. I will need to wait until I can get someone to do this for me.

Will try and check out the Start in Safe Mode in the meantime.

Firefox comes in two or more folders on all computers. They are;

Maintenance: (Programs Folder) <Windows Only> Firefox itself: (Programs Folder) And two folders in the profile of each user on the computer for each Firefox profile for that user.

If you remove the Firefox folder, the user profiles would not be affected.

Hi My helper chose to reinstall as described by FredMcD, thank you.

I carefully (manually) backed up all my tabs and bookmarks, but they survived the re-install. Now I just have to go and find my Add-ons again.

Is there still a "restore closed tab" add on anywhere? That is one I found really useful.

Thanks again.

PS yes the malfunctioning log-in now works.

GreenGreat said

Hi My helper chose to reinstall as described by FredMcD, thank you.

Does this mean the problem is gone?

Is there still a "restore closed tab" add on anywhere? That is one I found really useful.

Go to the Mozilla Add-ons Web Page {web Link} (There’s a lot of good stuff here) and search for what you want.

Hi it looks as if I now have another problem.

I now can't use hyperlinks in a document (although I can from an email) to open a browser page. Instead I get the message "This operation has been cancelled due to restrictions in effect on this computer. Please contact your system administrator."

This wasn't happening before. I don't have a "system administrator" and I don't know what to do about it. Any suggestions?

As you now have a different program, and this problem is solved;

Please go to the top of any support.mozilla.org web page and use the Ask A Question link; https://support.mozilla.org/en-US/questions/new Select the product for what the problem is (Firefox or whatever).

Now select the category for the problem. At the bottom is Other.

Describe the problem in brief (one line). Then press <enter>. The website will display any prior posts that might help you. If nothing on the list can help, at the bottom press the button; None Of These Solve My Problem.

Now enter all the relative information on the problem. At the bottom of this, you can Add Images.

Under this is Troubleshooting Information. Please press the Share Data button. This will let us look at your system details. No Personal Information Is Collected.

Note that login issues can be caused by corrupted cookies and it might help to clear the cookie from involved domains, so if it happens again then try some basic steps.

This issue can be caused by corrupted Cookies or Cookies that are blocked.

• check the permissions for the domain in the currently selected tab in "Tools -> Page Info -> Permissions"
• https://support.mozilla.org/en-US/kb/fix-login-issues-on-websites-require-passwords

Clear the cache and remove the Cookies from websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences).

"Clear the cache:

• Options/Preferences -> Privacy & Security -> Cached Web Content: "Clear Now"

"Remove the Cookies" from websites that cause problems.

• Options/Preferences -> Privacy & Security -> "Use custom settings for history" -> cookies: "Show cookies"

You can reload web page(s) and bypass the cache to refresh possibly outdated or corrupted files.

• hold down the Shift key and left-click the Reload button
• press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
• press "Command + Shift + R" (Mac)

If you use extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) that can block (wanted) content (Adblock Plus, NoScript, Ghostery, Privacy Badger, uBlock Origin) always make sure such extensions do not block (wanted) content.

• make sure your extensions and filters are updated to the latest version

There is Tracking Protection that can block (wanted) content.

• check the location/address bar for special icons.
• https://support.mozilla.org/en-US/kb/tracking-protection-firefox

@FredMcD thank you I get it. It looks like it's still a Firefox issue, but I will go and open a new query if I can't find anything by Googling the problem.

Many thanks.

@ cor-el Thank you probably time to do a cookie clean-up anyway, thanks for your suggestions.