[ns] error in mesh.tcl

Hi everyone I am getting this error when am running mesh.tcl from the wimax patch ( http://cng1.iet.unipi.it/wiki/index.php/Ns2mesh80216) with ns-2.33 (_o4 cmd line 1) invoked from within _o4 cmd run-identifier 1 invoked from within catch $self cmd $args ret invoked from within if

[ns] error running mesh.tcl

Hi everyone, I am trying to work in Wimax mesh architecture for which i am using ns 2.33 and ns2mesh patch which i downloaded from this site: http://cng1.iet.unipi.it/wiki/index.php/Ns2mesh80216 but as i try to run the mesh.tcl example i get an error which says: warning: using backward