Oracle :REP-52266: The in-process Reports Server rep_user failed to start.oracle.reports.RWException: IDL:oracle/reports/RWException:1.0

 Here is the solution I got :

1. Search the file rwnetwork.conf
2. Change the lines

From

<multicast channel="228.5.6.7" port="14021" timeout="1000" retry="5"/>
<!--namingService name="Cos" host="127.0.0.1" port="14021"/-->

To

<!--multicast channel="228.5.6.7" port="14021" timeout="1000" retry="5"/-->
<namingService name="Cos" host="127.0.0.1" port="14021"/>