Solution : https://service.sap.com/sap/support/notes/1544367 (SAP Service marketplace login required)
Key words : 
balance sheet structure definition, runtime error conne_import_wrong_comp_leng occurs, balance sheet structure, balance sheet structures, balance sheet items, exception cx_sy_import_mismatch_error occurs, runtime error occurs, transparent tables fagl_011, function group f037, attached correction instructions
Related Notes : 
       
| 1553851 | Bal. sht struct.: Runtime error CX_SY_IMPORT_MISMATCH_ERROR | 
| 1519781 | IMPORT_ALIGNMENT_MISMATCH instead of incorr component length |