check this:

• see if there are updates for your graphics drive drivers

https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

• disable protected mode in the Flash plugin (Flash 11.3+ on Windows Vista and later)

https://forums.adobe.com/message/4468493#TemporaryWorkaround

• disable hardware acceleration in the Flash plugin

https://forums.adobe.com/thread/891337 See also:

• http://kb.mozillazine.org/Flash#Troubleshooting

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

A little more on the theme of Flash: Since Flash can cause this problem and it is used pervasively through the web, I suggest the following to minimize potential issues with Flash during your troubleshooting:

(1) To avoid unnecessary pain on sites where Flash is not actually essential, try setting Flash to Click-to-Play ("Ask to Activate"). This will delay Flash from starting on a page until you approve it.

To set "Ask to Activate", open the Add-ons page using either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. Look for "Shockwave Flash" and change "Always Activate" to "Ask to Activate".

With this setting, when you visit a site that wants to use Flash, you should see a notification icon in the address bar and usually (but not always) one of the following: a link in a dark gray rectangle in the page or an infobar sliding down between the toolbar area and the page.

The plugin notification icon in the address bar typically looks like a small, dark gray Lego block. (If it's red, Flash needs updating.)

The delay in activating Flash can help distinguish between problems caused on initial page load, styling, and script activation vs. loading/running Flash.

If you see a good reason to use Flash, and the site looks trustworthy, you can go ahead and click the notification icon in the address bar to allow Flash. You can trust the site for the time being or permanently.

But some pages use Flash only for tracking or playing ads, so if you don't see an immediate need for Flash, feel free to ignore the notification! It will just sit there in case you want to use it later.

(2) A common cause of unresponsive script errors on Windows Vista and higher is the protected mode feature of the Flash player plugin. That feature has security benefits, but seems to have serious compatibility issues on some systems. You can disable it using the Add-ons page. Either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. On the right side, find "Shockwave Flash" and click the More link. Then uncheck the box for "Enable Adobe Flash protected mode" and try that for a day to see whether it helps.

FredMcD and jscher2000, I am so grateful for your kind responses to my earlier query.

My graphic's drivers are up to date, and I had already disabled hardware acceleration, although I have not yet disabled the 'Protected Mode' for the flash plugin.

What I have done this morning however, as per the above suggestion is to set the Flash instruction to 'Ask to Activate' Since doing that I have been in and out of the previously troublesome sites and without wishing to speak too soon I have not yet had a repeat of the 'Firefox is not responding' message. I am hopeful that this may have solved the problem. I will monitor it carefully throughout the day, and if the issue does not raise its head again I will likely mark the issue as 'Resolved'. It certainly does look as though the Flash components on certain websites could have been the major factor that was causing me such frustration.

Thank you both, again I appreciate your willingness to help.

Regards,

Alan (aka OldBaptist)

You're welcome.

Hello,

I am glad to hear that your problem has been resolved. If you haven't already, please select the answer that solves the problem. This will help other users with similar problems find the solution more easily.

Thank you for contacting Mozilla Support.

Well I left it just over a day, and I'm pleased to say that the 'Firefox not responding' problem has not happened again. It seems that solution was to set the 'Flash' instruction to 'Ask to Activate'. Since I did that I have had a much more successful and less frustrating browsing experience.

Thank you to jscher2000 and FredMcD for your help.

Regards,

Alan