Hi

What other add-ons do you have installed in Firefox?

Have you tried turning off NoScript completely?

Here are my other extensions: Adblock Plus DuckDuckGo Privacy Essentials Facebook Container Firefox Relay Norton AntiTrack

I did just now turn all of these off and still get same results; often, when going to sign on a black screen flashes then just shows blank afterward.

Update, I read this post: https://support.mozilla.org/en-US/questions/1344665

and then ran Firefox in Troubleshoot Mode

The problem did not occur, which sounds then like it may be either one of my extensions or hardware acceleration; I will test each extension one at a time as the related article says and see if that is the fix

some sites use anti-bot scripts and your adblockers might be interfering with it.