Hi, just loaded the service on the Winhost site and get this exception when I try and use it. Works from my local machine and from another hosted site in Windows 2003/IIS6 undet dotnet V4. Have been looking at other sites re the error and no luck. Have tried: setting endpoints setting windows security setting full trust setting service reporting with no luck. I used the WCF Rest service Template 40 with VS2010 for development. The IIS directory is set for DotNet 4.0 All the web.config adjustments have no effect. Any ideas?