Can you try Firefox Safe Mode to see if the problem goes away? You can restart in Firefox Safe Mode by either:

• Clicking the menu button , click Help and selecting Restart with Add-ons Disabled, or;
• Holding the option key while starting Firefox.

If the issue is not present in Firefox Safe Mode your problem is probably caused by an extension, theme, or hardware acceleration.

Let us know how you get on.

bmk825 said

I re-downloaded Firefox and reinstalled. But to no avail. Won't open links in web pages. Can do it in Safari. will download Chrome. But if I can't fix this, I will have to abandon Firefox.

Seems to work. Thanks!

Firefox Safe Mode is a tool used to help track down issues like yours - it shouldn't be used for daily browsing.

Please follow the steps in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause.