VBA now getting Runtime Error 13 - Type Mismatch but used to work perfectly

I've used this code for over a year with no problem. This time it copies and pastes the first sheet of each workbook in the folder to the master workbook like it is supposed to, but then hangs up and give me an Error 13 Type Mismatch on this line (which is the third to last line in the code):

For i = UBound(varLinks) To LBound(varLinks) Step -1

The macro is:

Private Sub CommandButton1_Click()
Dim Fpath As String, Fname As String
     
    With Application
        .ScreenUpdating = False
        .Calculation = xlCalculationManual
        .EnableEvents = False
    End With
     
    Fpath = "S:\Accounting\News NOP\" ' change to suit your directory
    Fname = Dir(Fpath & "*.xls")
     
     
    With Workbooks("NOP.xls") 'MUST BE OPEN
        Do While Fname <> ""
            If Fname <> .Name Then
                Workbooks.Open Fpath & Fname
                 'MOVE ONLY IF NOT   SAVING ON CLOSE. IF SAVING, USE COPY.
                Workbooks(Fname).Sheets(1).Move After:=.Sheets(.Sheets.Count)
            End If
            Fname = Dir
        Loop
    End With
     
    With Application
        .ScreenUpdating = True
        .Calculation = xlCalculationAutomatic
        .EnableEvents = True
    End With
    Dim i As Integer
Dim varLinks As Variant
varLinks = ActiveWorkbook.LinkSources(xlLinkTypeExcelLinks)
For i = UBound(varLinks) To LBound(varLinks) Step -1
ActiveWorkbook.BreakLink varLinks(i), xlLinkTypeExcelLinks
Next i
     
End Sub

I would really appreciate any help you can give me on this. Thanks!

You will get that error if varLinks is empty.

Thanks, Norie!