I got this error :
Lambda function handler threw an uncaught exception: No serializer found for class software.amazon.events.rule.ResourceModel$ResourceModelBuilder and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain: software.amazon.cloudformation.proxy.ProgressEvent["callbackContext"]->software.amazon.events.rule.CallbackContext["resourceModelBuilder"])
This means there is a setter/getter or relevant annotation missing. Can you post the code and complete exception for further comment/analysis?