Sub Macro_1()
Dim ws As Worksheet, c As Range
Set ws = Sheets("BD")
For Each c In Range(ws.[H2], ws.[H65000].End(xlUp)) ' H65000
If c = "X" And (c.Offset(, 1) <> "Passage" Or c.Offset(, 1) <> "Reunion") Then
MsgBox "Dans l'onglet BD, des bureux inaffectés sont mal renseignés," & _
vbCrLf & vbCrLf & "Merci de renseigner la colonne I de la valeur Passage ou Réunion !", vbOKOnly + vbExclamation, " Attention !": Exit Sub ' Exit si trouvé
End If
Next c
End Sub