Hi Dhananjay, I think there have been some similar problems to yours regarding this problem and I haven’t been able to help much, but I think it would be a good idea if you attach your simulation file (if possible) for me and others to observe your progress and be able to make changes and see if we can help. Thank you.
P.S. As soon as the problem in this forum is solved, yours is hopefully solved too:
http://staging.optiwave.com/forums/topic/error-during-simulation/