Creating a Table of contents with a page range

[yualbert92]

We started off with using this code:

Sub CreateTableOfContents()
' Determine if there is already a Table of Contents
' Assume it is there, and if it is not, it will raise an error
' if the Err system variable is > 0, you know the sheet is not there
Dim WST As Worksheet
On Error Resume Next
Set WST = Worksheets("TOC")
If Not Err = 0 Then
' The Table of contents doesn't exist. Add it
Set WST = Worksheets.Add(Before:=Worksheets(1))
WST.Name = "TOC"
End If
On Error GoTo 0

' Set up the table of contents page
WST.[A2] = "Table of Contents"
With WST.[A6]
.CurrentRegion.Clear
.Value = "Subject"
End With
WST.[B6] = "Page(s)"
WST.Range("A1:B1").ColumnWidth = Array(36, 12)
TOCRow = 7
PageCount = 0

' Do a print preview on all sheets so Excel calcs page breaks
' The user must manually close the PrintPreview window
Msg = "Excel needs to do a print preview to calculate the number of pages. "
Msg = Msg & "Please dismiss the print preview by clicking close."
MsgBox Msg
ActiveWindow.SelectedSheets.PrintPreview

' Loop through each sheet, collecting TOC information
For Each S In Worksheets
If S.Visible = -1 Then
S.Select
ThisName = ActiveSheet.Name
HPages = ActiveSheet.HPageBreaks.Count + 1
VPages = ActiveSheet.VPageBreaks.Count + 1
ThisPages = HPages * VPages

' Enter info about this sheet on TOC
Sheets("TOC").Select
Range("A" & TOCRow).Value = ThisName
Range("B" & TOCRow).NumberFormat = "@"
If ThisPages = 1 Then
Range("B" & TOCRow).Value = PageCount + 1 & " "
Else
Range("B" & TOCRow).Value = PageCount + 1 & " - " & PageCount + ThisPages
End If
PageCount = PageCount + ThisPages
TOCRow = TOCRow + 1
End If
Next S
End Sub

From this source: https://msdn.microsoft.com/en-us/library/office/ff841199.aspx

And it produced a table of contents with the page ranges, but once we ran a spell check and added some new work sheets it completely went bonkers when we ran it again.
Does anyone have any idea what went wrong? Does anyone have a better code to produce page ranges?

Thank you