Type about:preferences#advanced<Enter> in the address bar. Under Advanced, Select General. Look for and turn off Use Hardware Acceleration.

Type about:addons<enter> in the address bar to open the Add-ons Manager. Hot key; <Control>(Mac=<Command>) <Shift> A)

On the left side of the page, select Appearance. Then select Default.

Now restart Firefox.

It could be the work of one of your add-ons. Type about:addons<enter> in the address bar to open your Add-ons Manager. Hot key; <Control>(Mac=<Command>)<Shift> A)

In the Add-ons Manager, on the left, select Extensions. Disable a few add-ons, then Restart Firefox.

Some added toolbar and anti-virus add-ons are known to cause Firefox issues. Disable All of them.

If the problem continues, disable some more (restarting FF). Continue until the problem is gone. After, you know what group is causing the issue. Re-enable the last group ONE AT A TIME (restarting FF) until the problem returns.

Once you think you found the problem, disable that and re-enable all the others, then restart again. Let us know who the suspect is, detective.

Couldn't find use hardware acceleration -- but NO SCRIPT appears to have been the culprit. With that off and everything else on, my gmail opens properly. Thank You!

Glad to help. Safe Surfing.

Denni1250 said

Gmail standard view has stopped opening in my Firefox browser, I just get an error message about a problem with Java. So I updated and activated Java.

The Gmail site does not need the Java Plugin in order to work. Note the Java Plugin and JavaScript in Firefox to two different things. JavaScrip was originally going to be called LiveScript as that would have helped with the confusion between the two over the years.

http://kb.mozillazine.org/JavaScript_is_not_Java