Solution : https://service.sap.com/sap/support/notes/506127 (SAP Service marketplace login required)
Key words : 
~ftp/specific/isoil/46c/notes/note, error message 'unit gal entry missing, 'unit gal entry missing, terms settlement statement error, settlement statement document fails, -mine-specific note, settlement statement inactive, support uom gal, important supplementary information, import transport sogk013913
Related Notes : 
       
| 512081 | IS-OIL / IS-MINE: CRTs 29-30 for SAP_APPL | 
| 387861 | Order of IS-OIL / IS-MINE 4.6C Notes (SAP_APPL) | 
| 47531 | IS-OIL / IS-MINE / IS-CWM correction guideline |