Solution : https://service.sap.com/sap/support/notes/191270 (SAP Service marketplace login required)
Key words : 
additional key words, enter field mlst_mandt, upgrade implement note 191264, phase act_45a, sap indexes, table mlst, database system, error message, undo note 82252, note 82252
Related Notes : 
       
| 435140 | Additional information on upgrading to Basis 4.6D (APO 3.1x | 
| 420371 | Add. info on upgrading to Basis 4.6C SR2 (NDI upgrade) | 
| 390062 | Additional information about upgrading to 4.6C SR2 | 
| 327285 | Additions to upgrade to 4.6C SR1 | 
| 304597 | Additions to upgrade to Release 4.6C FCS | 
| 192949 | Additional info for upgrade to 4.6C | 
| 191264 | Incorrect indexes for table MLST | 
| 179373 | Additional info for upgrade to Rel.4.6B | 
| 117668 | Additional info: Upgrading to 4.5B | 
| 82252 | PS Info System, ADABAS: Timeout, long runtimes |