Let’s do a full clean re-install;

Note: Firefox comes in three 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.

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

( Did firefox re-install & problem still exists. Tried using both the new profile the install created and the old one (that kept all the bookmarks, etc) as the default and still got the "firefox has stopped working & windows will close program...." message.

Problem exists whether or not I'm in safe mode

Start your Computer in safe mode with network support. Then start Firefox. Try Secure websites. Is the problem still there?

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode Starting Any Computer In Safe Mode; Free Online Encyclopedia

OK - when I did that, had no problems/crashes - tried several secure sites where I'd had the problem & they all worked fine.

So, what's the next step to getting back to normal? (FYI - everything worked fine in Chrome even when NOT in safe mode, if that makes a difference)

That means something on the computer is causing the issue. As a test, disable your protection programs. If the problem goes away, contact their support.

Good morning ... Really appreciate your time & help ok - here's what happened when I disabled Bitdefender......

At first, the problem seemed to go away. Enabled parts one at a time - testing to see if I could get to Firefox - Options (one of the things that'd been causing the crashes) without getting the "stopped working" message & seemed fine at first - even when back to everything enabled. Thought maybe it was Bitdefender problem, but then it started up again the next time I went to the "options" page in firefox (had changed nothing since the last time it worked) Restarted computer & still problems. Went back & disabled Bitdefender again & still had the problem -- even with everything disabled & also with one part at a time disabled (nothing had updated in between those times in Bitdefender) Then got the "firefox closed unexpectedly" box - 2-3 times in a row. Refreshed Firefox & it opened fine - but the problem is still there.

Problem only seems to come up when trying to go to a different part of a webpage (firefox - options), trying to open a Microsoft word file (pdf files open fine) that was either sent from a trusted source or tried to download from secure page (ie - university of idaho) -- or trying to upload photos from my computer to website that I've used multiple times before (including right before the firefox update). In all of these cases, if I use Chrome instead of Firefox, I can complete the actions

It could be Bitdefender and something else.

I sent a support "ticket" in to Bitdefender so will keep fingers crossed that they have some ideas - will update here if that solves it or not. In the meantime, guess I'll just have to use Chrome for the things that have problems