Solution : https://service.sap.com/sap/support/notes/554287 (SAP Service marketplace login required)
Key words :
comc_pr_mappingwhere target_name = 'crmt_bsp_prd_odc_gtinuom', measure/gtin' tab, assign package crm_bsp_model_il_prod_map, create program crm_bsp_prod_mapping_delete, terms gtin, program error, support package 03, report crm_bsp_prod_mapping_delete, product maintenance, remains selected