https://userapps.support.sap.com/sap/support/knowledge/en/2619298
2619298 - Unexpected error occured during the repository upgrade - SAP PD | SAP Knowledge Base...
Unexpected error is raised during the repository upgrade from PD 16.6.2.5220 to PD 16.6.5.5587. The output displays: Unexpected error while executing SQL...
the repository