Solution : https://service.sap.com/sap/support/notes/1331893 (SAP Service marketplace login required)
Key words : 
previous lca build 20 patch level 001, significantly earlier date existed, installation file lc750051a4120_2-nnnnnnnn, lca routine sim_session_control due, 1 lca build 20 patch level 001, 1 lca build 20 patch level 002, unjustified lca error code 18757, system requirement aix - livecache 7, 1 lca build lower, lca routine setup_matrix_change
Related Notes : 
       
| 905189 | liveCache for SCM 4.X caused to crash after start on HP IPF | 
| 753528 | LCA builds on SAP Support Portal | 
| 737752 | Termination of the MAX DB/liveCache installation on AIX 5.1 | 
| 720261 | System requirement AIX - liveCache/MaxDB 7.4 to 7.9 | 
| 719652 | Setting initial parameters for liveCache 7.5, 7.6, 7.7 | 
| 713381 | Importing liveCache Version 7.5.00 for SAP SCM 4.1 | 
| 710166 | Feature list for liveCache/MaxDB 7.5.00 | 
| 487972 | Operating system parameterization of liveCache |