The converter detected that one or more of the parameters that were passed to its main entry point do not have valid storage addresses to which the converter could refer and obtain the value.
Ensure that each parameter passed to the XML converter has a valid non-null storage address unless a particular parameter can be null as defined by the converter call interface. For example, passing a null address for the XML buffer address to the language structure to XML converter will cause the required size of the XML buffer to be returned instead of performing XML conversion.