Server exception in event-unregister

We are getting from time to time the following exceptions on the server:

ServiceStack.HttpError: Subscription ‘ybADfzuTnoYhuMVTgvOH’ does not exist
at ServiceStack.ServerEventsUnRegisterService.Any(UnRegisterEventSubscriber request)
at lambda_method(Closure , Object , Object )
at ServiceStack.Host.ServiceRunner`1.Execute(IRequest request, Object instance, TRequest requestDto)

URL of the request for this error is appname/event-unregister?id=ybADfzuTnoYhuMVTgvOH

Why do these exceptions happen?

Can we ignore them?

It’s when the ServerEvents client sends a request to unregister itself, but it’s connection has already been removed from the server. It can be ignored.