org.mule.runtime.deployment.model.api.policy.PolicyRegistrationException: Error occured registering policy

SYMPTOM

A customer not using parallel deployed is seeing java.lang.NullPointerException errors. Below is an example of the error:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'HTTP_Request_configuration_jms-stopper_0002': Cannot create inner bean '(inner bean)#41ec0b87' of type [org.mule.runtime.module.extension.internal.config.dsl.connection.ConnectionProviderObjectFactory$$EnhancerByCGLIB$$fc09cb67] while setting bean property 'connectionProviderResolver'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#41ec0b87': Cannot create inner bean '(inner bean)#2ad2edd5' of type [org.mule.runtime.module.extension.internal.config.dsl.parameter.TopLevelParameterObjectFactory$$EnhancerByCGLIB$$56b31a01] while setting bean property 'parameters' with key [<<proxyConfig>>]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#2ad2edd5': Error setting property values; nested exception is org.springframework.beans.PropertyBatchUpdateException; nested PropertyAccessExceptions (2) are:

PropertyAccessException 1: org.springframework.beans.MethodInvocationException: Property 'parameters' threw exception; nested exception is java.lang.NullPointerException
PropertyAccessException 2: org.springframework.beans.MethodInvocationException: Property 'annotations' threw exception; nested exception is java.lang.NullPointerException

SOLUTION

During April of this year 2022, there was fix applied (Issue#W-10672687/SE-23764) for the error in question which can be referenced under the link below:
https://docs.mulesoft.com/release-notes/mule-runtime/mule-4.4.0-release-notes#april-2022

Please note, to fully enable the changes the following system property will need to configured:

mule.enable.byteBuddy.objectCreation=true

Please take a look at the article How to Set Mule and Java System Properties at Startup in Various Environments to know how this property can be applied.

This will enable the library to generate Java classes dynamically at Runtime. The fix applied was in the MRT April 2022 patch, but in order to fully enable the fix the property mentioned needs to be also enabled.

After reviewing the associated internal tickets and previous reported issues associated with the error stack, there was recommendation to enable the property without parallel deployment. Please note, the issue cannot be reproduced at times, but we are recommending to add the property to confirm it assists on resolving the issue.