What I believe they want is to restrict access to certain areas of the website to members only so when a member or guest tries accessing it they need to enter their log ins
Hey there I also do the same with my tech blog I persoanlly use aMember Pro
you can set up different plans and different protected directories however this isn't free so I would seqarch Amember pro alternatives
To access your account portal: https://x10hosting.com/sso/login/
Have you tried clearning you cache from your browser. Also try adding a index.html or index.php to see if that fixes the error I had the same error some time back