Solution : https://service.sap.com/sap/support/notes/67921 (SAP Service marketplace login required)
Key words : 
0a -> personnel administration -> personnel administration -> 'converting files prel, pu12_conversion800748  yj-ytt family subty conversion due, operation btchk107916    rpu30000 conversion problems110697    screen header, 5a - reduce runtime - t558a119327    error message rp785, menu -> release notes -> complete list -> release notes, generic object services assigned incorrectly526031 upgrade, 1h86241     legal change patches / support packages, task catalog326712 cancelling work time events, conversion rpucpc50121843    hr-pm/fi-fm, patched source releases83728    check table t510q
Related Notes : 
       
| 374172 | Q&A: Master Note for Conversions/Upgrades - Canada. | 
| 202169 | Additional Info: Upgrade to 4.6C - DB2/400 | 
| 178823 | Additional Information: Upgrade to 4.6B - DB2/400 | 
| 162117 | Additional Information: Upgrade to 4.6A - DB2/400 | 
| 141661 | Additional Info: Upgrading to 4.5B DB2/400 | 
| 114792 | HR upgrade, special feat. HR-PSG, Public Sector | 
| 108377 | Additional Info: Upgrading to 4.5A DB2/400 | 
| 105438 | Collective note on HR upgrade 3.0A-3.0F | 
| 100195 | RPUCPC00: termination DBIF_RSQL_INVALID_RSQL | 
| 99379 | Additional Info: Upgrading to 4.0B DB2/400 | 
| 91709 | Addition upgrade to 4.0B | 
| 91692 | Additional Info: Upgrading to 4.0A | 
| 76604 | Additional Info: Upgrading to 3.1H |