XML Parsing Error: not well-formed

Hi,

I get the "XML Parsing Error: not well-formed" when I set the XML Data Document - Setting for "Field Output" to "Normal". This setting would normally output the field rendered by Views. e.g. instead of <nid></nid> I need it to be the label I created <referencenumber></referencenumber>

Setting to RAW displays the XML document but with RAW fields.

I'm running Drupal 7.44 with Views 7.x-3.14

Has anyone else had this issue?