It won't do any harm to try removing those ticks.
However 'long running script' messages can occur through something entirely separate to your web browser hogging all of a computer's processing power, leaving it unable to work properly. The biggest cause (by far!) is the updating element of Microsoft's own anti-virus software (a sub-program called MsMpEng.exe) which seems to get stuck in a loop. (I've lost count of the number of computers I've seen that happening on!)
So it could well be your anti-virus program (or something else not directly related to your browser) that's actually the cause of the problem.
It's time to come out of the Dark Ages and ditch Internet Explorer. (It was pathetic when it was first introduced and it's just got worse over the years). Depending upon which set of figures you choose to believe, somewhere between 5% and 12% of all desktop users are currently using Internet Explorer:
http://upl.co/uploads/BrowserShare1526318254.jpg
However other surveys have shown that the vast majority of those users are businesses, with the figure for home users probably being closer to 2%. Given that people have to make an active choice to move away from IE (as that's what comes on their computers to start with), it shows just how reviled Internet Explorer actually is!
Switch to either Chrome (which, as those statistics show, is by far the most popular desktop browser in the world)
https://www.google.co.uk/chrome/
or Firefox (which appears to be the most popular browser here among AB members)
https://www.mozilla.org/en-GB/firefox/
Further, if you're currently using Microsoft's own anti-virus software, switch to Avast:
https://www.avast.com/index
Then your browser problems should be a thing of the past.