Hi Rajesh,
Based on the log, I could see that selname variable got resolved to null. So when you try to do selname.length in the for loop, a NullPointerException would be thrown and the control would go to catch block after which an empty forward is being thrown.
I guess this is the reason why you are getting the below exception
SRVE0293E: [Servlet Error]-[action]: java.lang.IllegalArgumentException: The path of an ForwardConfig cannot be null
So, please check why the selname variable is getting resolved to null?
Regards,
Sanjeev.