Solution : https://service.sap.com/sap/support/notes/100290 (SAP Service marketplace login required)
Key words : 
menu path edit -> set, thetranslation memory terms, translation memory tables, translation environment exists, translation environment senn, terms translation, senn solution, transaction senn, symptom translation, translation environment
Related Notes : 
       
| 520295 | Changing F1 help of a data element or a message | 
| 520157 | Creating F1 help for a data element | 
| 316032 | |
| 127294 | Billing due list: Incorrect text in the dialog box | 
| 124789 | DADS-TDS 1998: Legal changes (06.05.1999) | 
| 124061 | DADS-CRC 1998: Legal changes (20.04.1999) | 
| 115917 | BRC : Bordereau récapitulatif des cotisations | 
| 100295 | Translation work lists for a specific dev. class | 
| 98752 | Migration proposal pools (Release 3.0F/3.1x) |