Macro to copy and paste between workbooks

[Bobbrown]

I have two Workbooks one named master and the other slave.
I have created a macro to copy a range of data from a sheet named DATA in the master workbook to a sheet called DataCopyMaster in the slave workbook and then make the Records sheet active before saving and closing the slave workbook, which all works fine. I wanted to add this to the BeforeClose event of the master workbook so I can ensure the slave updates every time the master is closed but nolonger works once added to the BeforeClose event.
<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o> </o>
When I close the Master workbook I get a Visual basic runtime error runtime error ‘9’
Script out of range
It appears to code runs to the line:

Sheets("DataCopyMaster").Select

<o> </o>

Below is the macro I'm using in full.

Private Sub Workbook_BeforeClose(Cancel As Boolean)
    Range("A1:M50").Select
    Selection.Copy
    ChDir "C:\DATA\My Documents"
    Workbooks.Open Filename:="C:\DATA\My Documents\TestSheetSlave.xls"
    Sheets("DataCopyMaster").Select
    Range("A1:M50").Select
    ActiveSheet.Paste
    Range("A1").Select
    Sheets("Records").Select
    ActiveWorkbook.Save
    ActiveWindow.Close
    Application.CutCopyMode = False
    Range("A1").Select
End Sub

<o> </o>
<o> </o>
I don’t have a lot of experience with coding and I am sure I’m missing something simple here but would appreciate any assistance.

TB.