Let’s do a full clean re-install;

Download Firefox For All languages And Systems {web link}

Save the file. Then Close Firefox.

Using your file browser, open the Programs Folder on your computer.

Windows: C:\Program Files C:\Program Files (x86) Note: Check Both Folders

Mac: Open the "Applications" folder. https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac

Linux: Check your user manual. If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it. See Install Firefox on Linux; https://support.mozilla.org/en-US/kb/install-firefox-linux

If you downloaded and installed the binary package from the Firefox download page, simply remove the folder Firefox in your home directory. http://www.mozilla.org/firefox#desktop ++++++++++++++++++++++++++++ Look for, and remove any Mozilla or Firefox program folders. Do not remove the Mozilla Thunderbird folder if there is one.

Do Not remove any profile folders.

After rebooting the computer, run a registry scanner if you have one. Then run the installer. +++++++++++++++++++++++++++ If there is a problem, start your Computer in safe mode and try again.

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode This shows how to Start all Computers in Safe Mode; Free Online Encyclopedia

Why should fix require an uninstall & reinstall?

Sometimes files get corrupted. A full clean reinstall would remove such files as well as reload the registry.

Sometimes files get corrupted. A full clean reinstall would remove such files as well as reload the registry.

Sounds like a stab @ a possible fix, if that is the problem.

I would prefer to determine the problem, & then fix it, for certain.

Also, correct me if I'm wrong, but wouldn't that procedure erase/delete/destroy my open tabs, and all their history?

Wouldn't care to do that.

What I was attempting to do was bring this problem to the attention of the Mozilla folks, so that they could hopefully look @ it, id the problem & fix it.

If I merely got to a forum, that is a bunch of users, I did something wrong. I created an account sent the ? to Mozilla & hoped to have it fixed by them.

I don't believe this is a one off, & that I am the lone ranger. I wouldn't even care about the reverting to 63.0.3, except that it loses my tabs, & I have to upgrade to 64 in ordder to reload my tabs. \

Bucar00 said

I would prefer to determine the problem, & then fix it, for certain.

Many of us would like to know the exact problem and its cause. But sometimes that can not be done.

Also, correct me if I'm wrong, but wouldn't that procedure erase/delete/destroy my open tabs, and all their history?

I wouldn't even care about the reverting to 63.0.3, except that it loses my tabs, & I have to upgrade to 64 in ordder to reload my tabs.

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.

What I was attempting to do was bring this problem to the attention of the Mozilla folks, so that they could hopefully look @ it, id the problem & fix it.

If I merely got to a forum, that is a bunch of users, I did something wrong. I created an account sent the ? to Mozilla & hoped to have it fixed by them.

Sometimes the problem is not Firefox per se, but something outside or corruption. We here who answer questions have between us a lot of experience with all kinds of problems.

Once we have determined that the problem is a programming bug, we can create a bug report for the Mozilla developers to check out.