Solution : https://service.sap.com/sap/support/notes/838360 (SAP Service marketplace login required)
Key words : 
issue error message m7 821, delete storage location segments, storage location segments, plant & storage loc, batch-managed materials, terms m7821 reason, xfeld            development class, mb            short description, storage location segment, mchb entries                       enter
Related Notes : 
       
| 867627 | MB5B: Incorrect display for batch materials | 
| 62272 | Poor response times during ATP-Check with batches |