Solution : https://service.sap.com/sap/support/notes/517296 (SAP Service marketplace login required)
Key words : 
abap runtime error sapsql_where_cant_scan due, abap runtime error sapsql_array_insert_duprec, abap runtime error occurs, call function module i_mass_variant_save, exception                  short textnot_saved                  variant, message short text 'variant &, calling message class ', mass maintenance terminates, mass maintenance results, maximal 1000 selection conditions
Related Notes : 
       
| 709077 | MASSD: Saving of a variant terminates with runtime error | 
| 557702 | FAQ for mass maintenance | 
| 330416 | Sel.cond.>8kbytes: ABAP dump SAPSQL_WHERE_CANT_SCAN |