Cannot open pdf files generated from online sites

I don’t seem to be able to open a pdf file linked from certain websites despite my checking that it is ‘positive’ site

Only seems to have happened recently and a shame as I can’t even download the pdf either as its meant to open up first in a new window, which it does but all I get is a black screen with the pdf link in the url bar

what avast version do you have … free / AIS / Premier
could be related to Ransomware shield

Applies to Avast Premier, Avast Internet Security

Ransomware Shield - FAQs
https://support.avast.com/en-eu/article/Antivirus-Ransomware-Shield-FAQ
https://support.avast.com/en-eu/article/Use-Ransomware-Shield

I have the free avast (downloaded at beginning of year)

What program are you using to open the pdf ???
You can open a pdf directly in Chrome and Edge. You can also use the Avast Secure Browser to open a pdf file.

Im having the same problem in chrome and it seems to be coming from avast antitrack because when i turn it off, antitrack, the pdf shows up.