0 Visual Studio 2008: Unable to start debugging on web server. An authentication error occurred... http://www.realtechnology.com/Default.aspx?tabid=59&EntryID=27 My dev server is a Win 2003 machine with IIS 6.0.  I've got a number of web sites set up which I reference via URLs such as http://site1.localhost, http://site2.localhost, etc.  By putting e ... en-US