Console users get HTTP 401.3 message.
HTTP Error 401.3 - Unauthorized
You do not have permission to view this directory or page because of the access control list (ACL) configuration or encryption settings for this resource on the Web server.
ITMS 7.x, 8.x
Authenticated users did not have read access to %windir%\Microsoft.net\Framework64\v2.0.50727
Add authenticated users or reset to default permissions for the apsnet_filter.dll 32 and 64 bit folders.
Many other items can cause this problem including permissions on the folder with the .aspx files.