Report Server URL Not Vaild Error

[dan0]

I have an application that needs the report server URL for that application's sql instance. Based on the fact that it is an instance the report server URL should be:

http://servername/reportserver$InstanceName

When I enter the above, on the server that has the SQL server instance, the web-page displays the report server URL and report server version number.

However, when I enter the above URL in the application, it returns an error stating:

The Report Server URL entered is not valid

Following is the URL for the reports manager, which the application accepts:

http://servername/reports$InstanceName

Does anyone know what is or could be wrong with the report server URL and how to fix the issue(s)?

Thanks.