VBA Runtime error '1004'. AutoFilter method of Range class failed

Question

Everytime I execute my Macro (below) to search for a string that is entered into my search box, I get a Runtime error '1004'. AutoFilter method of Range class failed. I've tried looking for an answer to this problem on here for a while but nothing seems to provide me with a solution.

When I hit 'Debug' it highlights the below section of the code.

    DataRange.AutoFilter _
    Field:=myField, _
    Criteria1:=SearchString, _
    Operator:=xlAnd

I realise that this isn't much info but any help would be extremely appreciated.

P.S. I'm a complete novice with VBA and copied the code off a website that did a step by step guide to creating a search filter in Excel.

Sub SearchBox()

Dim myButton As OptionButton
Dim SearchString As String
Dim ButtonName As String
Dim sht As Worksheet
Dim myField As Long
Dim DataRange As Range
Dim mySearch As Variant

'Load Sheet into A Variable
  Set sht = ActiveSheet

'Unfilter Data (if necessary)
  On Error Resume Next
    sht.ShowAllData
  On Error GoTo 0

'Filtered Data Range (include column heading cells)
  Set DataRange = sht.Range("A5:Z40000") 'Cell Range
  'Set DataRange = sht.ListObjects("Table1").Range 'Table

'Retrieve User's Search Input
  mySearch = sht.Shapes("UserSearch").TextFrame.Characters.Text 'Control Form
  'mySearch = sht.OLEObjects("UserSearch").Object.Text 'ActiveX Control
  'mySearch = sht.Range("A1").Value 'Cell Input

'Determine if user is searching for number or text
  If IsNumeric(mySearch) = True Then
    SearchString = "=" & mySearch
  Else
    SearchString = "=*" & mySearch & "*"
  End If

'Loop Through Option Buttons
  For Each myButton In sht.OptionButtons
    If myButton.Value = 1 Then
      ButtonName = myButton.Text
      Exit For
    End If
  Next myButton

'Determine Filter Field
  On Error GoTo HeadingNotFound
    myField = Application.WorksheetFunction.Match(ButtonName, DataRange.Rows(1), 0)
  On Error GoTo 0

'Filter Data
  DataRange.AutoFilter _
    Field:=myField, _
    Criteria1:=SearchString, _
    Operator:=xlAnd

'Clear Search Field
  sht.Shapes("UserSearch").TextFrame.Characters.Text = "" 'Control Form
  'sht.OLEObjects("UserSearch").Object.Text = "" 'ActiveX Control
  'sht.Range("A1").Value = "" 'Cell Input

Exit Sub

'ERROR HANDLERS
HeadingNotFound:
  MsgBox "The column heading [" & ButtonName & "] was not found in cells " & DataRange.Rows(1).Address & ". " & _
    vbNewLine & "Please check for possible typos.", vbCritical, "Header Name Not Found!"

End Sub

Answer 1

check the value of myField, it must be between 1 and 26 because your range is A -> Z.