This is the default page for the site container for the web site of the Microsoft Dynamics NAV Web Server Components. You are viewing this page instead of the Microsoft Dynamics NAV Web Client because the URL that you entered in the browser address bar is in a format that is no longer valid.
To view Microsoft Dynamics NAV Web Client, you must include the web server instance name for the web site in the URL, as shown in the following example:
Contact your system administrator to get the web server instance name, and then enter the correct URL in the browser address bar.
You can find more details about URL format here: Opening a Page in the Microsoft Dynamics NAV Web Client by Using a URL