When attempting to open the DA (Desktop Authority) Manager the error “Server Error in ‘/DesktopAuthorityConsole Application.is displayed.

There can be multiple causes for this error. In this instance the console is not pointing to the correct location for the default website: C:\inetpub\wwwroot.
Go to IIS | Default Web Site| Advanced Settings and point to the Physical Path to C:\inetpub\wwwroot. Once the changes are made you should be able to open Desktop Authority Manager.