Je te mets ça au cas où:
spinner = 1
For L = 1 To nbcourse
&&& For N = 1 To nbvague(L)
&&&&& course(spinner, 1) = L &&&
c´est là qu´il y a problème
&&&&& course(spinner, 2) = N
&&&&& Msg = " Entrer le DECALAGE DE TEMPS ( en seconde) "
&&&&& Title = " DECALAGE DE TEMPS"
&&&&& course(spinner, 5) = InputBox(Msg, Title)
&&&&& If course(spinner, 5) = " " Then
&&&&&&& MsgBox ( "décalage = 0 pour vague " & N & " de la course " & L)
&&&&&&& course(spinner, 5) = 0
&&&&& End If
&&&&& spinner = spinner + 1
&&& Next N
Next L