Thanks !

Work for Waterfox, but don't work for Palemoon (search bar not working). Please update !

I've solved the problem. Update the script.

What was happening is a race condition where the script gives up looking for the placeholder of the dialog before it appears in the html code. And then was only hiding the dialog and not dismissing it. That's why you could not focus on the search input field. Apparently Palemoon is slower to render the page on the same computer compared to FF or chrome.

I've modified the code to use another method of getting hold of the html element.
It should work properly now. Don't hesitate to post a new message.