Macros giving Run-time error '9' on all machines except mine

Hello, I have set up a central sheet with employee information in it and wrote macros in a few other sheets that pulls the information it needs from the central sheet. This allows me to enter the information once and then pull the information in as I need it.

However, while the macro functions perfectly on my machine, it gives a Run-time error '9' error on any other machine I try to run it on. I have checked for Add-Ins and References and everything matches. The highlighted line is the one that the debugger highlights. My first thought was that the machine didn't have access to the file opened two lines above, but when I looked, the file had opened as was intended. I am at a loss to explain this. What am I missing?

Thanks much in advance,
Scott Tucker

Private Sub cmdUpdate_Click()
Dim ITT, CAD
    Application.ScreenUpdating = False
    Workbooks.Open Filename:="\\uberserver\SHARED\CallCenter\Sprint\Workforce\Central Agent Database.xls"
    Set ITT = ThisWorkbook.Sheets("AgentDB")
    Set CAD = Workbooks("Central Agent Database").Sheets("Agent Information")
    CAD.Columns("D:D").Copy
    ITT.Columns("A:A").PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
        :=False, Transpose:=False
    CAD.Columns("C:C").Copy
    ITT.Columns("B:B").PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
        :=False, Transpose:=False
    CAD.Columns("F:F").Copy
    ITT.Columns("C:C").PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
        :=False, Transpose:=False
    ActiveWindow.Close
    ThisWorkbook.Activate
    Sheets("Invalid Transfers").Select
    Application.ScreenUpdating = True
End Sub