https://userapps.support.sap.com/sap/support/knowledge/en/3527068
3527068 - KBA: Negative Value in field PAPVL in the Idoc | SAP Knowledge Base Article
In the outbound IDOC segment /SAPSLL/E2CCEIDO CUIE, value "-1" is determined for field PAPVL. This results in an error message being received back from customs.