NullPointerException in EnumMap when auto generating wadl with Jersey

Question

I am using Tomcat 7, Jaxb2 and Jersey1.11. I have a class EnumProperty which inherits from an abstract class Property.

@XmlAccessorType(XmlAccessType.FIELD)
public class EnumProperty extends Property<Enum> {
@XmlElement(name = "property_value", nillable = true)
private Enum value;

    public EnumProperty() {
        setValueType(PropertyValueTypeEnum.ENUM);
    }

    @Override
    public Enum getValue() {
        return value;
    }

    @Override
    public void setValue(Enum value) {
        this.value = value;
    }
}

There are other sub classes for the Property class. In addition, I have another class, Entity, which holds a collection of properties. I have also a resource which returns in one of its sub resources a Collection. When I try to generate my application wadl I receive a NullPointerException. I isolated the problem to the EnumProperty class. Can anyone please help me understand where the problem is?

java.lang.NullPointerException
java.util.EnumMap.<init>(Unknown Source)
com.sun.xml.bind.v2.model.impl.RuntimeEnumLeafInfoImpl.<init>(RuntimeEnumLeafInfoImpl.java:87)
com.sun.xml.bind.v2.model.impl.RuntimeModelBuilder.createEnumLeafInfo(RuntimeModelBuilder.java:109)
com.sun.xml.bind.v2.model.impl.RuntimeModelBuilder.createEnumLeafInfo(RuntimeModelBuilder.java:85)
com.sun.xml.bind.v2.model.impl.ModelBuilder.getClassInfo(ModelBuilder.java:228)
com.sun.xml.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:104)
com.sun.xml.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:85)
com.sun.xml.bind.v2.model.impl.ModelBuilder.getClassInfo(ModelBuilder.java:213)
com.sun.xml.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:99)
com.sun.xml.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:85)
com.sun.xml.bind.v2.model.impl.ModelBuilder.getTypeInfo(ModelBuilder.java:319)
com.sun.xml.bind.v2.model.impl.TypeRefImpl.calcRef(TypeRefImpl.java:96)
com.sun.xml.bind.v2.model.impl.TypeRefImpl.getTarget(TypeRefImpl.java:73)
com.sun.xml.bind.v2.model.impl.RuntimeTypeRefImpl.getTarget(RuntimeTypeRefImpl.java:62)
com.sun.xml.bind.v2.model.impl.RuntimeTypeRefImpl.getTarget(RuntimeTypeRefImpl.java:55)
com.sun.xml.bind.v2.model.impl.ElementPropertyInfoImpl$1.get(ElementPropertyInfoImpl.java:78)
com.sun.xml.bind.v2.model.impl.ElementPropertyInfoImpl$1.get(ElementPropertyInfoImpl.java:81)
java.util.AbstractList$Itr.next(Unknown Source)...