Serializing 'naked' enum throws exception java.lang.IllegalAccessException

[readlearncode]

Serialising an enum throws the following edited exception:

javax.json.bind.JsonbException: Error getting value on: 
sun.reflect.annotation.AnnotatedTypeFactory$AnnotatedParameterizedTypeImpl@1f57539
...
Caused by: java.lang.IllegalAccessException: 
Class org.eclipse.yasson.internal.model.GetFromGetter can not access a member of class 
sun.reflect.annotation.AnnotatedTypeFactory$AnnotatedTypeBaseImpl 
with modifiers "public final"
	at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:102)
	at java.lang.reflect.AccessibleObject.slowCheckMemberAccess(AccessibleObject.java:296)
	at java.lang.reflect.AccessibleObject.checkAccess(AccessibleObject.java:288)
	at java.lang.reflect.Method.invoke(Method.java:491)
	at org.eclipse.yasson.internal.model.GetFromGetter.internalGetValue(GetFromGetter.java:28)
	at org.eclipse.yasson.internal.model.GetValueCommand.getValue(GetValueCommand.java:34)

The enum:

public enum Binding {
    HARD_BACK {
        public String toString() {
            return "Hard Back";
        }
    }, SOFT_BACK {
        public String toString() {
            return "Soft Back";
        }
    }
}

The serialisation code: JsonbBuilder.create().toJson(Binding.HARD_BACK);

Dependecies:
org.eclipse/yasson: 1.0
javax.json.bind-api: 1.0
org.glassfish/javax.json: 1.1
javax.json/javax.json-api: 1.1

CODE: https://github.com/readlearncode/Java-EE-8-Sampler/blob/master/json-b-1-0/src/main/java/com/readlearncode/devWorks/overview/EnumExample.java
TEST: https://github.com/readlearncode/Java-EE-8-Sampler/blob/master/json-b-1-0/src/test/java/com/readlearncode/devWorks/overview/EnumExampleTest.java