Solution : https://service.sap.com/sap/support/notes/328942 (SAP Service marketplace login required)
Key words : 
additional key words saplfaci awsys logical system, prerequisites solution program correction, external data transfer, message types fidcmt, logical system, bkpf-awsys, current system, fi document, rfbibl00 'd', direct input
Related Notes : 
       
| 831089 | FI: AWSYS is set during the parking in FB01 | 
| 416678 | Line item: special field BKPF-AWSYS not filled | 
| 392286 | RAABST01: Local logical system not defined | 
| 382990 | ALE FI: AWSYS blank, F1308 & other conseqnt. errors | 
| 375320 | No FI document display via PCA line items | 
| 367821 | M/AM: FI document issue (jhtfk-belnr) remains blank | 
| 361892 | RAZUGA01: B2001 "Local logical system is not defined" | 
| 355764 | Logical system: correction for Note 328942 | 
| 320834 | Composite note: Updating own log.System in application |