Hi @Explorer1
It looks like you are using some service in your servlet, eg.
@Reference
private CustomReferenceService customReferenceService;
Please ensure that all the services being used in servlet is in active state.
Also I believe you must have a Impl class that is implementing the service. So try to use
@Reference
private CustomReferenceServiceImpl customReferenceServiceImpl;
Hope that helps!
Regards,
Santosh