In the RestDispatcherServlet#init (line 112), all currently registered endpoints are being registered to the servlet. During this process, the Endpoint will be initialized. We had a scenario were one of the endpoint could not be initialized properly due to a wrong Generic type. The initialization process did throw a guice error without any real description of the failure, but this was not really the problem.
The servlet threw an exception and did not register the rest of the valid endpoint keeping us in the dark about what in which endpoint did do wrong.

I would like to suggest a try..catch around the line "registerEndpoint(endpointDefinition)" so developers know which Endpoint definition failed to register, and so that the rest of the endpoint are correctly registered (because they are fine).