Error 91 in VBA using classes - class

Question

I'm currently trying to implement a Clark & Wright Savings Heurisitc in VBA, but I'm currently facing some problem. I'm fairly new to VBA, and this error (91) keeps apearing on similar situations, which lead me to believe I'm missing some crucial knowledge. Next I present you the code:
Public Sub CWsavings()
Dim i As Integer
Dim j As Integer
Dim k As Integer
Dim aux As Integer
Dim d As Integer
Dim r As Integer
Dim Cu(200) As customer
Dim De(12) As Depot
For i = 1 To 200
Set Cu(i) = New customer
Cu(i).custID = i
Cu(i).longitude = ThisWorkbook.Sheets("Folha1").Cells(i + 1, 2)
Cu(i).latitude = ThisWorkbook.Sheets("Folha1").Cells(i + 1, 3)
Cu(i).lt = ThisWorkbook.Sheets("Folha1").Cells(i + 1, 4)
Cu(i).et = ThisWorkbook.Sheets("Folha1").Cells(i + 1, 5)
Cu(i).weekdemand = ThisWorkbook.Sheets("Folha1").Cells(i + 1, 6)
Cu(i).peakdemand = ThisWorkbook.Sheets("Folha1").Cells(i + 1, 7)
Cu(i).D1 = ThisWorkbook.Sheets("Folha1").Cells(i + 1, 8)
Cu(i).D2 = ThisWorkbook.Sheets("Folha1").Cells(i + 1, 9)
Next i
For j = 1 To 12
Set De(j) = New Depot
De(j).depotID = j
De(j).Dname = ThisWorkbook.Sheets("Folha1").Cells(i + 1, 13)
De(j).latitude = ThisWorkbook.Sheets("Folha1").Cells(i + 1, 14)
De(j).longitude = ThisWorkbook.Sheets("Folha1").Cells(i + 1, 15)
De(j).ncust = ThisWorkbook.Sheets("Results").Cells(j, 7)
De(j).nroute = 0
For k = 1 To De(j).ncust
aux = ThisWorkbook.Sheets("Results").Cells(j + 1, 10 + k)
Call De(j).SetCustomer(Cu(aux), k)
Next k
Next j
For d = 1 To 12
Dim M(30, 30) As Double
Dim maxsav As Double
Dim maxpos(2) As Integer
Dim connorder(676, 2) 'order of connections for routing
Dim it As Integer
it = 0
For i = 1 To De(d).ncust
For j = 1 To De(d).ncust
M(i, j) = CalcSavings(De(d), De(d).customer(i), De(d).customer(j)) ' error here
Next j
Next i
itbegin:
maxsav = 0
maxpos(1) = 0
maxpos(2) = 0
For i = 1 To De(d).ncust
For j = 1 To De(d).ncust
If i <> j Then
If M(i, j) > maxsav Then
maxsav = M(i, j)
maxpos(1) = i
maxpos(j) = j
End If
End If
Next j
Next i
it = it + 1
connorder(it, 1) = maxpos(1)
connorder(it, 2) = maxpos(2)
If it < De(d).ncust * De(d).ncust - ncust Then
M(maxpos(1), maxpos(2)) = 0
GoTo itbegin
End If
Next d
End Sub
Public Function CalcSavings(d As Depot, C1 As customer, C2 As customer)
Dim id As Double
Dim dj As Double
Dim ij As Double
id = DeptDist(C1, d)
dj = DeptDist(C2, d)
ij = CustDist(C1, C2)
CalcSavings = id + dj - ij
End Function
The class Depot:
Public depotID As Integer
Public Dname As String
Public latitude As Double
Public longitude As Double
Private customers(200) As customer
Public ncust As Integer
Private routes(500) As route
Public nroute As Integer
Public Sub addcust(C As customer)
ncust = ncust + 1
Set customers(ncust) = C
End Sub
Public Sub addroute(R As route)
nroute = Me.nroute + 1
Set routes(Me.nroute) = R
End Sub
Public Property Get customer(i As Integer) As customer
customer = customers(i)
End Property
Public Sub SetCustomer(C As customer, i As Integer)
Set customers(i) = C
End Sub
Public Property Get route(i As Integer) As route
route = routes(i)
End Property
Public Sub SetRoute(R As route, i As Integer)
Set routes(i) = R
End Sub
(Class depot Updated)
And the class Customer:
Public custID As Integer
Public latitude As Double
Public longitude As Double
Public lt As Double
Public et As Double
Public weekdemand As Integer
Public peakdemand As Integer
Public D1 As Integer
Public D2 As Integer
I'm sorry for the long post, any help would be appreciated.

Answer 1

Final answer...
VERY ODDLY, (not that odd, when you really look at it, but) you need to use Set even in your Get properties. I guess the reason behind this is because you're returning an object, and even though that object may already exist, you're not going to use that very object. A copy is used instead and Set becomes vital to initialize that copy.
For example, here's what your "get customer" should look like :
Public Property Get customer(i As Integer) As customer
Set customer = customers(i)
End Property
I guess it all makes sense; your array is private, and therefore you wouldn't want to pass the exact object that is contained inside that array, or it'd be counter-logic.
I think I found it... again...!
Try this :
Public Sub SetCustomer(C As customer, i As Integer)
Set customers(i) = C
End Sub
Notice customer(i) was replaced by customers(i)
EDIT : Deleted previous answer, as I was mostly fishing.