HP Laptop running win 8.1
Took ages to find out that Avast free is blocking (inconsistently but more often than not) all https sites even google search, and microsoft sites on my browsers. I had to faff around with avast to get into the webshield via settings - active protection - webshield - customise - and untick https scanning. Now I can access https sites again.
Thought I’d post this as 1) it needs fixing and 2) took me hours and hours to suss it as theres not a lot on the web about it and I couldn’t use chrome or ie properly because of the issue, so hopefully this may help someone.