How to stop Avast from alerting on Chrome extension

Every time I start my Win8.1 laptop and then Chrome, Avast says that this extension

https://chrome.google.com/webstore/detail/humble-new-tab-page/mfgdmpfihlmdekaclngibpjhdebndhdj

is a bad extension and asks if I want it removed, saying it has a poor rating among Avast users. I have had it on my PC at home for over two years, have had it on my Win8.1 laptop since I got said laptop, it hasn’t caused any problems on either system and I have never got an alert on it on my Win7 PC.

How do I get Avast to stop alerting on that extension?

https://forum.avast.com/index.php?board=54.0

Thank you! I looked around the forum, but must have overlooked that section

You’re welcome.