[ns] error in tcl file

when i am trying to generate nam file it gives error : Flow 1 starts at time 0.00 Segmentation fault (core dumped) plz give me solution how to solve this problem mkc.tcl---

[ns] error in TCL file

Hi Folks, Why I am getting this error I have made all the changes in the NS... invalid command name Agent/NewProto while executing Agent/NewProto create _o59 invoked from within catch $className create $o $args msg invoked from within if [catch $className create $o $args msg] { if