NservicebusPubSub

Answer 1

It's hard to tell without seeing the rest of your NServiceBus initialization code, but my guess would be that you didn't configure a subscription storage for your publisher. It is very likely that when the subscription requests arrived at this endpoint that NServiceBus wrote an error to the log explaining this. The solution should be as simple as including .MsmqSubscriptionStorage() to your initialization code, or .DbSubscriptionStorage() if you want to scale out.