Solution : https://service.sap.com/sap/support/notes/1598547 (SAP Service marketplace login required)
Key words : 
-leading ledger fiscal variant, fiscal year variant reason, fiscal year variant provided, previous fiscal year, future fiscal year, shortened year variant, fagl_mig075 error issued, migration customizing issues, fy variant, terms fagl_mig075
Related Notes : 
       
| 672255 | Shortened fiscal year/changing fiscal periods |