Server stack trace:      
  在 Microsoft.AspNet.SignalR.PersistentConnection.GetConnectionId(HostContext context, String connectionToken)     
  在 Microsoft.AspNet.SignalR.PersistentConnection.ProcessRequest(HostContext context)     
  在 Microsoft.AspNet.SignalR.Hubs.HubDispatcher.ProcessRequest(HostContext context)     
  在 Microsoft.AspNet.SignalR.Owin.CallHandler.Invoke(IDictionary`2 environment)     
  在 Microsoft.AspNet.SignalR.Owin.Handlers.HubDispatcherHandler.Invoke(IDictionary`2 environment)     
  在 Microsoft.Owin.Host.SystemWeb.OwinCallContext.Execute()     
  在 Microsoft.Owin.Host.SystemWeb.OwinHttpHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object extraData)    Exception rethrown at [0]:      
  在 Microsoft.Owin.Host.SystemWeb.Infrastructure.ErrorState.<>c__DisplayClass1.<GetRethrowWithNoStackLossDelegate>b__0(Exception ex)     
  在 Microsoft.Owin.Host.SystemWeb.Infrastructure.ErrorState.Rethrow()     
  在 Microsoft.Owin.Host.SystemWeb.CallContextAsyncResult.End(IAsyncResult result)     
  在 Microsoft.Owin.Host.SystemWeb.OwinHttpHandler.EndProcessRequest(IAsyncResult result)     
  在 System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()     
  在 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

The connection id is in the incorrect format.

Microsoft.Owin.Host.SystemWeb