When the element is a child element of complex type and the maximum occurrence of this element is unbounded, the schema is not valid. The JSON parser restricts you from extracting multiple instances of an element.
The maximum occurrence of child elements under complex type must be 0 or 1 with the order indicator as choice for the complex type in a schema. When you change the maximum occurrence as 1 to validate the schema, you can extract one instance of the element at a time.
You can use the maximum occurrence as unbounded in the choice order indicator of a complex type in the schema.