How to work around Excel 2016 halting without message when trying to assign variable to VBProject? - excel

Question

System Details.
Windows 10
Excel 365 64-bit V16.0 (Apps for Enterprise)
Issue.
I have a macro that opens a file, checks if the user has allowed programmatic access to the VBA Project in the trust center and raises an alert if they have not. This works fine on windows 7 machines with both 32bit and 64bit Excel from 2013 onwards.
The specific problem I am having on the Windows 10 machine is that when workbooks.open(path) is executed the file opens but in the VBA Project explorer window the VBAProject object for that file does not appear. I also get a popup saying that code cannot be run in break mode when I try this while stepping through the code. When run on Win 7 with this version of Excel and others both 32 and 64-bit the VBAProject object appears and no popup is generated.
This lack of the VBA Project causes an issue later when I run set vbproj = ActiveWorkbook.VBProject. At this point when stepping through the code execution halts with no messages at all. The Project pops up in the Project explorer window and it takes me to a module in the opened workbook. This gets opened with Design Mode turned on and when you click to turn it off I get an error message saying 'Macros have been disabled'
Notes
set vbproj = ActiveWorkbook.VBProject works fine if the file is open and the VBAProject is visible in the Project explorer window.
If the file being opened does not contain a macro then it works correctly.
I have made sure that the files are in a Trusted Location.
I have set Enable all macros in the Macro Settings of the Trust Center.
When opening the files manually I do not get any alerts that macros have been disabled by an administrator and I do not get any message asking if I want to enable macros.
I have looked at W10 group policies to see if there is one that would block VBAProjects / Macros from files opened via VBA and there does not appear to be one as far as I can see.
The Trust Center setting for programmatic access to the VBA Project does not matter to this test case. It will return True if it is allowed and False if it is not allowed.
This has been tested on another Windows 10 laptop with the same version of Excel 64-bit and it has the same result so is not an issue with a specific users laptop.
I removed the folder from the Trusted Location on the Windows 7 machine and the code still executes correctly and returns True/False.
In the actual macro this check is done for each opened file in a loop and the variant vbproj is used to remove data from the modules within that project. I have considered working around the issue by using Application.onTime and that may be a solution but have not spent much time on that and with how it halts it may not be viable.
Attempted Solutions
I have tried set wb = workbooks.open(path) to open the workbook and then using set vbproj = wb.VBProject but it has the same behavior as above.
I have tried doing ActiveWorkbook.Activate and similar actions to see if that will make the VBA project appear, it does not.
I have tried setting Application.FileValidation = msoFileValidationSkip before opening the file, this does not change the behavior.
I have tried setting Application.EnableEvents=False before opening the file, this does not change the behavior.
I have tried making vbproj a variant, an object and a VBProject, this does not change the behavior.
Steps to Recreate
Create a new workbook.
Put the below code into Module 1.
Function projectAccess()
Dim vbproj As Variant
On Error GoTo noaccess
Set vbproj = ActiveWorkbook.VBProject 'If access is denied an error is raised.
projectAccess = True
Exit Function
noaccess:
projectAccess = False
End Function
Sub openfile()
Dim filepath As String
filepath = Application.ThisWorkbook.Path
Workbooks.Open (filepath & "\openfile.xlsm")
Debug.Print projectAccess
End Sub
Save the workbook
Create a 2nd workbook, in my case it was called openfile.xlsm and put some code into Module 1.
put both workbooks in the same location and make sure it is a Trusted Location in Excel.
run openfile().
If successful the immediate window will display True / False depending on the Trust Center setting.
I am out of ideas. Any suggestions for some setting that I may have overlooked to make the Win 10 machines behave the same as the Win 7 machines or suggestions for a possible work around?
Even if it is a group policy setting that would be something I can raise with IT as long as I know what to ask for.
Many Thanks
Andrew
EDIT: Thanks to Rory in the comments the issue was making sure that the automation security was set like so Application.AutomationSecurity = msoAutomationSecurityLow as the way the new Win 10 + Office 64 systems have been set up by my IT dept is to have it default to msoAutomationForceDisable