Sometimes you can get the following error while trying to access some sites.
It looks like these errors are from Akamai or other CDN’s
Why is Akamai blocking me?
Why is Akamai blocking me? Part 2 & 3
Client Reputation Lookup
Akamai says they don’t block you, but the site can use tools and policies which could block you. To resolve the issue you should contact the web site owner and see if you can get unblocked and potentially get more details.
You can try doing a whois on the website domain to find the contact email.