Hi Jololi would you mind to test something.

First I assume that you are using Windows. Is it a fresh install or you are using it for some time?

What version of Firefox are you using? If you don't know how to check version go here --> https://support.mozilla.org/en-US/kb/find-what-version-firefox-you-are-using?redirectlocale=en-US&redirectslug=Finding+your+Firefox+version

Also would you mind to check if Firefox freezes when trying to watch a GIF image (you can try it on www.9gag.com) or trying to open Facebook or Youtube.

What is your computer system and Firefox?

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac Options) key, and then starting Firefox. Is the problem still there?

Hi logglog, Thanks for your reply. I am using Windows 7 Pro and Firefox 42.0. Firefox did not freeze when I watched GIF images at the indicated website. Thanks.

Hi, I hope we can solve this :)

Try out next

1. Delete Firefox profile Press windows key and type %APPDATA% find and delete Mozilla or Firefox folder (Don't worry firefox will automatical generate these folders again when started, this will just reset your settings. These settings are not deleted if firefox is reinstalled)

2. Disable hardware acceleration If 1. didn't work ( I actually don't expect it to work) try this. Type in the address bar " about:preferences#advanced " without quotes and uncheck Use hardware acceleration when available. http://i.imgur.com/PgcIOsV.png

3. Other software If 1. and 2. didn't work then disable any antivirus software or apple software and then see if your browser still freezes.

Try to start Firefox in Safe Mode by holding down the Shift (Mac: Options) key to see if that helps.

Create a new profile as a test to check if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Hi Hi logglog & FredMcD, When I started in safe mode, it froze after about 7 mn of use. Then I disabled the hardware acceleration as indicated, and so far it working normally. I will give an update later. Thanks for your tremendous support! Best.

You are welcome, I hope it works normally now. If it works feel free to click yes on "was this helpful to you? " :D

The second day I am using Firefox without any freeze! Keeping my fingers crossed. This has not happened for ages! Thanks to logglog for providing the solution, and to All others for their useful suggestions. This was a good learning experience for me.