I have two workbooks; Test Menu.xlsm and TestWB.xlsm both residing in
the C:\Data folder

The Test Menu.xlsm file has two command buttons (from Form Controls).
The first button 'OpenTestWB' opens the TestWB file, the second button
'CloseThisWB2' closes the Test Menu.file.

The TestWB.xlsm file has one command button (also from Form Controls)
which simply closes the TestWB file, 'CloseThisWB1' and returns to
Test Menu.xlsm.

The OpenTestWB code works fine as does the CloseThisWB1

The problem occurs for some users when they click on the
'CloseThisWB2' button on the Test Menu.xlsm which results in a
Microsoft Windows error message. However for others, clicking this
button does what it's supposed to, that is it closes the workbook.
Furthermore for those users who were getting the error message, if
they had another Excel file open when they clicked the CloseThisWB2'
button on the Test Menu.xlsm it worked fine.

To remedy the situation I replaced the ActiveWorkbook.close code on
Test Menu.xlsm to read Application.Quit.

Problem solved, but it is still a mystery I'd like to solve and I
appreciate any ideas you have or if you spot something in my code.
Our company uses Excel 2007 on Vista

Here's the code for both these test workbooks:

Test Menu.xlsm:
Sub OpenTestWB()
Dim Testwb As Workbook
Set Testwb = Workbooks.Open("C:\Data\TestWb.xlsm")
End Sub

Sub CloseThisWB2()
Application.DisplayAlerts = False
ActiveWorkbook.Close
End Sub


TestWB.xlsm:
Sub CloseThisWB1()
Application.DisplayAlerts = False
ActiveWorkbook.Close
End Sub



Thank you,

Rob