I'm playing around with DevDefined.OAuth - an OAuth consumer and provider implementation for .Net http://code.google.com/p/devdefined-tools/wiki/OAuth and on launching the ExampleConsumerSite project after configuring the service endpoints on my IIS 7 web server, I'm receiving the following error: Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Exception: Request for uri: http://localhost%3A8080/RequestToken.aspx?oauth%5Fcallback=oob&oauth%5Fnonce=94efde0b-dd45-4cee-8253-7496cef0b877&oauth%5Fconsumer%5Fkey=key&oauth%5Fsignature%5Fmethod=PLAINTEXT&oauth%5Ftimestamp=1252512419&oauth%5Fversion=1.0&oauth%5Ftoken=&oauth%5Fsignature=secret%2526 failed. status code: InternalServerError An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately. Source Error: [HttpException]: 'RequestToken' is not allowed here because it does not extend class 'System.Web.UI.Page'. at System.Web.UI.TemplateParser.ProcessError(String message) at System.Web.UI.TemplateParser.ProcessInheritsAttribute(String baseTypeName, String codeFileBaseTypeName, String src, Assembly assembly) at System.Web.UI.TemplateParser.PostProcessMainDirectiveAttributes(IDictionary parseData) [HttpParseException]: 'RequestToken' is not allowed here because it does not extend class 'System.Web.UI.Page'. at System.Web.UI.TemplateParser.ProcessException(Exception ex) at System.Web.UI.TemplateParser.ParseStringInternal(String text, Encoding fileEncoding) at System.Web.UI.TemplateParser.ParseString(String text, VirtualPath virtualPath, Encoding fileEncoding) [HttpParseException]: 'RequestToken' is not allowed here because it does not extend class 'System.Web.UI.Page'. at System.Web.UI.TemplateParser.ParseString(String text, VirtualPath virtualPath, Encoding fileEncoding) at System.Web.UI.TemplateParser.ParseReader(StreamReader reader, VirtualPath virtualPath) at System.Web.UI.TemplateParser.ParseFile(String physicalPath, VirtualPath virtualPath) at System.Web.UI.TemplateParser.ParseInternal() at System.Web.UI.TemplateParser.Parse() at System.Web.UI.TemplateParser.Parse(ICollection referencedAssemblies, VirtualPath virtualPath) at System.Web.Compilation.BaseTemplateBuildProvider.get_CodeCompilerType() at System.Web.Compilation.BuildProvider.GetCompilerTypeFromBuildProvider(BuildProvider buildProvider) at System.Web.Compilation.BuildProvidersCompiler.ProcessBuildProviders() at System.Web.Compilation.BuildProvidersCompiler.PerformBuild() at System.Web.Compilation.BuildManager.CompileWebFile(VirtualPath virtualPath) at System.Web.Compilation.BuildManager.GetVPathBuildResultInternal(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile) at System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile) at System.Web.Compilation.BuildManager.GetVirtualPathObjectFactory(VirtualPath virtualPath, HttpContext context, Boolean allowCrossApp, Boolean noAssert) at System.Web.Compilation.BuildManager.CreateInstanceFromVirtualPath(VirtualPath virtualPath, Type requiredBaseType, HttpContext context, Boolean allowCrossApp, Boolean noAssert) at System.Web.UI.PageHandlerFactory.GetHandlerHelper(HttpContext context, String requestType, VirtualPath virtualPath, String physicalPath) at System.Web.UI.PageHandlerFactory.System.Web.IHttpHandlerFactory2.GetHandler(HttpContext context, String requestType, VirtualPath virtualPath, String physicalPath) at System.Web.HttpApplication.MapHttpHandler(HttpContext context, String requestType, VirtualPath path, String pathTranslated, Boolean useAppConfig) at System.Web.HttpApplication.MapHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) I've noticed the oauth_token GET parameter is empty. On tracing this, the error source is from the line 12 of Default.aspx.cs page: IToken requestToken = session.GetRequestToken(); protected void oauthRequest_Click(object sender, EventArgs e) { OAuthSession session = CreateSession(); IToken requestToken = session.GetRequestToken(); if (string.IsNullOrEmpty(requestToken.Token)) { throw new Exception("The request token was null or empty"); } Session[requestToken.Token] = requestToken; string callBackUrl = "http://localhost:" + HttpContext.Current.Request.Url.Port + "/Callback.aspx"; string authorizationUrl = session.GetUserAuthorizationUrlForToken(requestToken, callBackUrl); Response.Redirect(authorizationUrl, true); } While I'm not sure if this has to do with configuring the service endpoints but I'm running the consumer project from VS2008 and hosting the service on IIS. Please advice.