Hi,
Could ypu please provide sapinst_dev.log. I need it from the first error message until the end.
Furthermore you should use SRS 15.7 SP121. If you check th software download center then you will see that only SAP Replication Server 15.7 SP121 has the additon
"EBF 22360: 15.7.1 SP121 - 64 Bit, also certif. for Bus Suite"
Regards,
Joachim