'Auto_Open' macro error occurs after 'Enable Editing' clicked.

Thanks for the  KB article 2745652.
I also found that I could also trap it at the 'Workbook_Open' & 'Workbook_Activate' event.

(ThisWorkbook' module)
Option Explicit
Dim WBprotected As Boolean

Private Sub Workbook_Open()
    If Application.ProtectedViewWindows.Count > 0 Then
        WBprotected = True
    End If
End Sub

Private Sub Workbook_Activate()
    If WBprotected = True Then
        Call Auto_Open          'Auto_Open will not automatically run
    Else
        'Auto_Open will automatically run in 'Module1'
    End If
End Sub

Thanks for the update, baldwin_it,

Idle curiosity, what was deficient about my answer?

Brian.

Did you try the 'KB article 2745652' article VB routine?
I could not get it to even be triggered as an event.
I copied the ''2745652' routines into the 'ThisWorkbook' object and inserted some 'Stop' syntax so as to step through the event process.  When opening the test spreadsheet from Outlook, it never stopped in any of the '2745652' code and produced the original error.  The 'Stop' normally works in other event routines, so I assume it should for  'oApp_WorkbookOpen', 'oApp_WorkbookActivate' & 'WorkbookOpenHandler'.


Yesterday I was able to get the routines I posted above to work without the '2745652' routines, but today I am not, so I am back to square one.  Any ideas as to what I am missing?

baldwin_it,

My ISP is having problems so I'm getting on-line very intermittently. Hopefully, I'll get back to you later today.

Edit: On seconds thoughts, this has been going on for long enough already without my internet problems causing you further delays. The question was obviously closed too early but if you have it reopened now, very few people are going to notice it, so please hit the "Request Attention" button, ask for the question to be deleted and then immediately open a new one with the relevant bits from here.

Brian.

I discovered today why my above routines were not working.   In addition to having an 'Auto_Open' routine in my workbook, I have 'Auto_Close' & 'SelectionChange' routines which were getting triggered prematurely and causing an error.

Here is the event order assuming the following security settings:
'Disable All Macros w/Notification'
& 'Enable Protected View for Outlook Attachments'

'Enable Editing' alert bar
'Enable Content' alert bar
Workbook_Open()
SelectionChange()
Auto_Close()
Workbook_Activate()
Auto_Open()

When 'SelectionChange' or 'Auto_Close' routines are executed while transitioning from 'Protected View' an error will occur whenever the workbook object is referenced.

I modified the 'ThisWorkbook' routines as follows:
Private Sub Workbook_Open()
    If Application.ProtectedViewWindows.Count > 0 Then
        WBprotected = True      
        Processing = True          
    End If                          
End Sub                      
Private Sub Workbook_Activate()
    If WBprotected = True Then
        Processing = False      'WkBk now enabled
        Call Auto_Open          'Auto_Open will not automatically run, so force it to run.
    Else
        'Auto_Open will automatically run
    End If
End Sub                      

I also added
       If Processing = True Then Exit Sub
to the beginning of the 'SelectionChange()' and 'Auto_Close' routines.

This stopped those routines from executing and causing an error and solved my problem.

Thanks for the interaction, I appreciate it.  Re-opening the Question is not necessary.

Thanks for the update, baldwin_it. I can see lots of people finding it a life-saver.