Userform works despite Run-Time Error 91. What's going on? - excel

Question

I am new to Userforms. I have created the following Userform which is called from a subroutine. The Userform picks up a range from a sheet and creates a corresponding number of textboxes and then checkboxes so as to allocate an original name with a new name.
The userform is created with the following:
Public Sub UserForm_Initialize()
'Declare variables
Dim txtBox As MSForms.TextBox
Dim comBox As MSForms.ComboBox
Dim i As Integer
Dim j As Integer
Dim n As Integer
Dim dist As Integer
Dim dstArr As Variant
Dim rng As Range
'Assign variables
Set rng = Range("Missing_MAERSK")
n = rng.Rows.Count
dist = 5
dstArr = Range("LU_Destination_Ports").Value
'Loop to add textboxes
For i = 1 To n
Set txtBox = UserForm1.Controls.Add("Forms.TextBox.1", Visible:=True)
With txtBox
.name = "txtBox" & i
.Value = rng(i)
.Height = 20
.Width = 150
.Left = 81
.Top = 30 + dist
.Font.Size = 10
End With
dist = dist + 20
Next i
'Loop to add list boxes
dist = 5
For j = 1 To n
Set comBox = UserForm1.Controls.Add("Forms.ComboBox.1", Visible:=True)
With comBox
.name = "comBox" & j
.List = dstArr
.Height = 20
.Width = 150
.Left = 315
.Top = 30 + dist
.Font.Size = 10
End With
dist = dist + 20
Next j
'Show userform
UserForm1.Show
End Sub
And then when the Replace Names button is clicked the following is ran:
Public Sub CommandButton1_Click()
'Close userform
Unload UserForm1
'This is the one
Dim cmb As MSForms.ComboBox
' Dim txt As MSForms.TextBox
Dim oldVal As String
Dim newVal As String
Dim rng As Range
Dim rng2 As Range
Dim n As Integer
Set rng = Range("MAERSK_Destin")
Set rng2 = Range("Missing_MAERSK")
n = rng2.Rows.Count
'Loop
For i = 1 To n
Set txt = Me.Controls("txtBox" & i)
Set cmb = Me.Controls("comBox" & i)
If cmb.Value <> "" Then
oldVal = txt.Value
newVal = cmb.Value
rng.Replace what:=oldVal, Replacement:=newVal
End If
Next i
End Sub
Let's say I populate Bangkok to Bangkok BMT, I get the following:
I think the issue might be with the way I call the values in the Command_Button1_Click sub.
Any advice would be appreciated.
Cheers

Answer 1

Figured out the problem.
According to this post: Call UserForm_Initialize from Module
a UserForm should not be initialized from outside the userform.
I was calling UserForm_Initialize() from my sub, so to rectify this I replaced it with UserForm1.Show