Dear Dimitri ,
Thank you.Table entries successfully imported after checking overwrite duplicate keys option while importing 
.
While processing the scenario, in EDI Separator Sender Channel we are facing the same error pointed out in Error in Edi Seperator Sender channel.
Our System is P1 7.4 and details of patch level is shown below.
Is it required any up gradation ?..Need your help..
Thanks,
Tibin