IIS 7.5 .ASPX 401.3 – Unauthorized for IUSR Account

After installing all prerequisite dependencies and setting up a XenApp 6.5 Web Interface 5.4 on IIS 7.5, I was getting the error “401.3 – Unauthorized: Access is denied due to an ACL set on the requested resource” whenever I tried to access the web interface front end using the default IUSR account for anonymous authentication. I tried every combination of troubleshooting I could think of: looked through IIS logs, changed the Anonymous Authentication credentials to use the Application pool identity instead of IUSR, changed the application pool’s identity to run as NetworkService instead of ApplicationPoolIdentity, added NTFS ACL read permissions for