Solution : https://service.sap.com/sap/support/notes/192665 (SAP Service marketplace login required)
Key words : 
individual upgrade phases            iv/    problems, euro local currency changeover directly, 6b additional key words, activate 'fixed point arithmetic', individual upgrade phasesiv/    problems, local currency changeovers, local currency changeover, /     miscellaneousii/    checks prior, applying hot packages, ii/    checks prior
Related Notes : 
       
| 179373 | Additional info for upgrade to Rel.4.6B | 
| 100084 | Release strategy of Euro Conversion (EURO-CNV) |