Runtime error 91 ? Need Help...

For l = 1 To lastr
'...
'...
l = Frow + 1
Next 

Sub find_transpose()
' Variables
Dim What As String 'Valeur Cherché
Dim Frow As Long 'Ligne Valeur Trouve
Dim Last_row As Long 'Derniere ligne recherche
Dim l As Long 'ligne
Dim Lr As Long 'Last row sheet 2
'Recopie Vendor
l = 1
Last_row = Range("B1000000").End(xlUp).Row + 2
lastr = Range("B1000000").End(xlUp).Row

Dim c, firstAddress 

Sheets(1).Activate
'Vendor
What = "Vendor" 'Variante recherché 

With Sheets(1).Range(Cells(l, 2), Cells(Last_row, 2))
    Set c = .Find(What) 
    If Not c Is Nothing Then 
        firstAddress = c.Address 
        Do 
            Frow = c.Row
            Cells(Frow, 3).Copy ' Copie de la cellule cherché
            'Collage en derniere ligne
            Sheets(2).Activate
            Lr = Range("A1000000").End(xlUp).Row + 1
            Cells(Lr, 1).PasteSpecial
            Sheets(1).Activate
            Set c = .FindNext(c) 
        Loop While Not c Is Nothing And c.Address <> firstAddress 
    End If 
End With
End Sub 

With Sheets(1)
    If Application.CountIf(Columns("A"), "vendor") > 0 Then
        Frow = Columns("A").Find("vendor", Range("A1"), xlValues).Row
        Data = Cells(Frow, "C").Value
    End If
End With
With Sheets(2)
     lr = .Range("A1000000").End(xlUp).Row + 1
     .Cells(lr, "A") = Data
End With