Issue with Ns2.29

Hello,

I am a beginner in Ns2 .
I'am trying to run the example attached bu I have this errors :

Simulation is running ... please wait ...
can't read "Node_(7)": no such element in array
    while executing
"return $Node_($id)"
    (procedure "_o3" line 3)
    (Simulator get-node-by-id line 3)
    invoked from within
"$self get-node-by-id [lindex $L 0]"
    (procedure "_o3" line 14)
    (Simulator compute-hier-routes line 14)
    invoked from within
"$self compute-hier-routes "
    invoked from within
"if [Simulator hier-addr?] {
$self compute-hier-routes 
} else {
$self compute-flat-routes
}"
    (procedure "_o3" line 2)
    (Simulator compute-routes line 2)
    invoked from within
"[Simulator instance] compute-routes"
    (procedure "Agent/rtProto/Static" line 2)
    (Agent/rtProto/Static init-all line 2)
    invoked from within
"Agent/rtProto/Static init-all"
    invoked from within
"if [info exists rtprotos_] {
foreach proto [array names rtprotos_] {
eval Agent/rtProto/$proto init-all $rtprotos_($proto)
}
} else {
Agent/rtProto/St..."
    (procedure "_o122" line 3)
    (RouteLogic configure line 3)
    invoked from within
"[$self get-routelogic] configure"
    (procedure "_o3" line 5)
    (Simulator run line 5)
    invoked from within
"$ns run"

Can you help me please?