How to stop Avast from blocking/deleting certain files I downloaded?

Avast Free Antivirus / Premium Security
1

I try to download a exstention for Chrome called Videostream Avast thinks its a treat and stops the download.
The only way I can get this download is if I stop Avast. But once I install Videostream and try to use it Avast deletes it.
How do I put an end to this? Avast no right to dictate on what I can do or not on my PC.

2
Avast thinks its a treat and stops the download.
What does avast say?

Avast Antivirus: Excluding certain files or websites from scanning
https://www.avast.com/faq.php?article=AVKB168#artTitle

3

http://screencast-o-matic.com/screenshots/u/Lh/1499813151103-67870.png

If this is what you are talking about, it’s working for me. ??? ??? ???