XML : xml is not valid - error 1002

I am struck by this error that I can't seem to resolve. I am getting an XML IS NOT VALID, error 1002.

I have checked certain xml validators online and they indicate xml is well formed. The xml is there to query an api but it doesn't seem to work.

Does anyone know what I'm doing wrong.

  <SERVICE_SEARCH_REQUEST>      <VERSION_HISTORY>APPLICATION_NAME=AppName XML_FILE_NAME =XMLFileName LICENCE_KEY=xxx-3939-xxxx-xxxx-xxx TS_API_VERSION = TSAPIVersion>          <XML_VERSION_NO>3.0</XML_VERSION_NO>      </VERSION_HISTORY>      <GEO_LOCATION_NAME>London</GEO_LOCATION_NAME>      <START_DATE>12 Jan 16</START_DATE>      <NUMBER_OF_NIGHTS>1</NUMBER_OF_NIGHTS>      <AVAILABLE_ONLY>TRUE</AVAILABLE_ONLY>      <GET_START_PRICE>true</GET_START_PRICE>      <ROOM_REPLY>          <ANY_ROOM/>      </ROOM_REPLY>      <ROOMS_REQUIRED>          <ROOM>              <OCCUPANCY>2</OCCUPANCY>              <QUANTITY>1</QUANTITY>          </ROOM>          <ROOM>              <OCCUPANCY>3</OCCUPANCY>              <QUANTITY>1</QUANTITY>          </ROOM>      </ROOMS_REQUIRED>  </SERVICE_SEARCH_REQUEST>    

response i'm getting is:

  Array ( [@attributes] => Array ( [CATEGORY] => XML Validation ) [VERSION_HISTORY] => Array ( [@attributes] => Array ( [APPLICATION_NAME] => AppName [XML_FILE_NAME] => XMLFileName [LICENCE_KEY] => LicenceKey [TS_API_VERSION] => TSAPIVersion ) [XML_VERSION_NO] => XMLVersionNumber ) [ERROR_NUMBER] => 1002 [ERROR_DESC] => XML is not valid )