I have a signalr that worked nice with 4.5 After upgraded to 4.6 it works ok on Win 2008 R2 , but does not work on Windows 2012 .
The error is :
System.InvalidOperationException: WebSockets is unsupported in the current application configuration. To enable this, set the following configuration switch in Web.config: <system.web> <httpRuntime targetFramework="4.5" /> </system.web> For more information, see http://go.microsoft.com/fwlink/?LinkId=252465. at System.Web.Util.SynchronizationContextUtil.ValidateMode(SynchronizationContextMode currentMode, SynchronizationContextMode requiredMode, String specificErrorMessage) at System.Web.HttpContext.AcceptWebSocketRequest(Func2 userFunc, AspNetWebSocketOptions options) at Microsoft.AspNet.SignalR.Transports.WebSocketTransport.AcceptWebSocketRequest(Func2 callback) at Microsoft.AspNet.SignalR.PersistentConnection.ProcessRequestPostGroupRead(HostContext context, String groupsToken) at Microsoft.AspNet.SignalR.TaskAsyncHelper.FromMethodT1,T2,T3,TResult --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.Owin.Mapping.MapMiddleware.d__0.MoveNext() --- End of stack trace from previous location where exception was thrown --- at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.StageAsyncResult.End(IAsyncResult ar) at System.Web.HttpApplication.AsyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) If I add httpRuntime targetFramework="4.5" to web.config , the application won't run at all.
