Solution : https://service.sap.com/sap/support/notes/779238 (SAP Service marketplace login required)
Key words : 
business area balance sheet, business area stays empty, t001-xgsbe reason, call transaction fb21, business area, transaction fb21, batch input, offsetting entry, terms f-38, standard system
Related Notes : 
       
| 334015 | Business area inheritance in the batch input |