Solution : https://service.sap.com/sap/support/notes/537347 (SAP Service marketplace login required)
Key words : 
relevant system -> extras -> delete imported requestsdepending, smts -> import overview -> double-click, file <upgdir>\buffer\shdall, command 'tp addtobuffer' creates, character 'carriage return', sap service marketplace, call transaction stms, wrong buffer format, directory <upgdir>\exe, previously empty buffer
Related Notes : 
       
| 603852 | Additional information about upgrading to SAP SCM 4.0 | 
| 587896 | Add. info on upgrade to SAP R/3 Enterprise Core 4.70 SR1 | 
| 484876 | Additional information about upgrading to SAP Web AS 6.20 | 
| 435140 | Additional information on upgrading to Basis 4.6D (APO 3.1x | 
| 420371 | Add. info on upgrading to Basis 4.6C SR2 (NDI upgrade) | 
| 401717 | Additional info on upgrading to SAP Web AS 6.10 (Basis) | 
| 390062 | Additional information about upgrading to 4.6C SR2 | 
| 335029 | Additions to the upgrade to Basis 4.6D (NDI Upgrade) |