Error message 401.3:

[jancat]

Error message 401.3: You do not have permission to view this directory or page using the credentials you supplied (access denied due to ACLs). Ask the Web server's administrator to give you access to 'C:\Inetpub\vhosts\sqladmin\mssql\app\connect.aspx'.

 

[alta]

I guess you have issue with mssql webadmin, please check that in IIS->web sites->sqladmin(default)->properties->directory security->authentication->tick on "enable anonymous user".