Macro Error: Invalid Outside Procedure

I'm adding a new macro and getting the error message Compile Error:Invalid outside procedure. I'm using the following code

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