Solution : https://service.sap.com/sap/support/notes/566449 (SAP Service marketplace login required)
Key words : 
system landscape directory, generally entered manually, terms sxmb_adm reason, warning appears indicating, service user entered, configure integration engine, appears indicating, service user, integration engine, transaction sxmb_adm
Related Notes : 
       
| 620103 | SAP Exchange Infrastructure 2.0 SR1 Installation | 
| 557414 | SAP Exchange Infrastructure 2.0 Installation |