It works, using new ValueSignal<>(Integer.class) in stead made the difference.
I actually did have a @Component on the SignalHost, but the NPE was of cause still there.
With the SignalFactory.IN_MEMORY_EXCLUSIV I just wanted to be explicit, but I guess it makes sense to have that scope as the default.
Anyway, I do find that signals are an improvement to the the business domain specific code and that is what matters to me.
Looking forward to the webinar, thanks.
Br Mikael