[ns] no such element in array

[Imen HEDFI]

hi,

i'm trying to simulate a handover scenario, after defining all the
components and traffic type i get the following error
INITIALIZE THE LIST xListHead
can't read "Node_(9)": 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 $L 1]"
   (procedure "_o3" line 15)
   (Simulator compute-hier-routes line 15)
   invoked from within
"$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 "_o321" 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"
   (file "sctpTest_modifié.tcl" line 326)
[root at localhost work]# no such element in array

there is similar error in the archives but no solution

can any one help me please
best regards


imen