Solution : https://service.sap.com/sap/support/notes/602318 (SAP Service marketplace login required)
Key words : 
communication structure ---> 'save' communication structure -> 'generate', communication structure ---> 'save' selet, improving system stability relating, select 'communication structure' -> 'change', 'obsolete' communication structure, communication structure -> 'enter', activate transfer structure, p_s_comm data object, generating transfer rules, detailed error message
Related Notes : 
       
| 1399123 | Consulting: Shared use of Transfer Structure | 
| 1111745 | RSAR_DDIC_NAME_CONFLICT does not discern multiple use | 
| 710348 | RSAR 245 template 'RSTMPL80' error code '7' |