VBA Code Works in Excel 2010 but not Excel 2013

Hello,

I am using a Worksheet that I have spent a long time working on. It will one day be implemented throughout our company for use on Estimates. I have been writing and testing this Workbook on a computer that has Excel 2010. However, it isn't working on other computers with Excel 2013.

I have checked:
1. Trust center -> Enable Macros Setting
2. Solver installed (although there is code without the solver that is also not working.
3. VBA Editor ->Tools -> References. 2010 = Microsoft Excel 14.0 Object Library. 2013 = Microsoft Excel 15.0 Object Library (Can't tell if this is the cause of my code, don't know enough about when late binding is needed)

Could someone with Excel 2013 let me know if they can determine why it is not working. I think there are several different instances causing errors and I am not sure where they are and how to fix them.

Thanks for any help/advice.

Here is some code that is failing....

Sub ShowDivisionTotals()

Application.ScreenUpdating = False

'Unlock Sheet
Call UnlockSheet

Sheets("Division Totals").Select
    With ActiveSheet.PivotTables("Division Totals").PivotFields("Division Seperators")
        .PivotItems("2").Visible = False
    End With
    
    With ActiveSheet.PivotTables("Division Totals").PivotFields("Secondary Seperators")
        .PivotItems("1").Visible = True
    End With
    

'Lock Sheet
Call LockSheet

Application.ScreenUpdating = True
    
End Sub

The subs being called are working for sure because I use them with key functions too and they work when I press Ctrl+U and Ctrl+L for example.