”Webpage is slowing down your browser” This is the new way the browser tells you there is a problem with the script program(s). https://support.mozilla.org/en-US/kb/warning-unresponsive-script?cache=no

https://support.mozilla.org/en-US/kb/task-manager-tabs-or-extensions-are-slowing-firefox

What's a script program? I click on Wait and this yellow bar returns. If I click Stop then the page won't load. Displaying the bar with these options is pretty useless so how do I stop it showing?

Most web pages are a combination of written text, pictures, and interactive areas (including links). A script is a program that manages such pages so that when you move the mouse or click on something, whatever is supposed to happen will happen.

this has gotten worse since an automatic update happened, now my curser is jumpy , and now get intermittent crackling sound

Please go to the top of any support.mozilla.org web page and use the Get Community Support link: https://support.mozilla.org/en-US/questions/new

Select the product for what the problem is (Firefox or whatever). Now select the category for the problem. At the bottom is Other.

Describe the problem in brief (one line). Then press <enter>. The website will display any prior posts that might help you. If nothing on the list can help, at the bottom press the button; ’’'None Of These Solve My Problem.

Now enter all the relative information on the problem. At the bottom of this, you can Add Images.

Under this is Troubleshooting Information. Please press the Share Data button. This will let us look at your system details. No Personal Information Is Collected.