VBA Circular Error

Function VLOOKAllSheets(Look_Value As Variant, Tble_Array As Range, _
Col_num As Integer, Optional Range_look As Boolean)
Dim wSheet As Worksheet
Dim vFound
On Error Resume Next
For Each wSheet In ActiveWorkbook.Worksheets
With wSheet
Set Tble_Array = .Range(Tble_Array.Address)
vFound = WorksheetFunction.VLookup _
(Look_Value, Tble_Array, _
Col_num, Range_look)
End With
If Not IsEmpty(vFound) Then Exit For
Next wSheet
Set Tble_Array = Nothing
VLOOKAllSheets = vFound
End Function

It is a vlookup across all worksheets, it is used on the index sheet. But it is causing a circular error when the search term is not found AND if the formula is in the same cell as the column index cell. I need an expert to adjust the code so that it doesn't do vlookup in the index/current sheet and the recursive error will be eliminated.