Signalr Error: The connectionid is in the incorrect format

Question

I have a web application that uses Signalr to display server notifications whenever a report is sent.

Recently I have received the error below, but searching the internet did not find out what can be:

Erro de Servidor no Aplicativo '/'.
The connection id is in the incorrect format.

Rastreamento de Pilha:

[InvalidOperationException: The connection id is in the incorrect format.]
   Microsoft.Owin.Host.SystemWeb.Infrastructure.<>c__DisplayClass1.<GetRethrowWithNoStackLossDelegate>b__0(Exception ex) +36
   Microsoft.Owin.Host.SystemWeb.CallContextAsyncResult.End(IAsyncResult result) +79
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +431
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +75
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +158

I’ve checked the publishing machine key and the server language

I read about webfarms and load balance, but my application runs on only 1 server, so these solutions didn’t suit me.

Does anyone know what it can be?

OBS: I did not put excerpt of code because this same application runs without problem in the servers of other clients... I imagine the problem is in some configuration of IIS or OS.