Running 64-bit Excel 2013 on Windows 8.1 Pro
Executing the Application.ActivateMicrosoftApp method with an invalid numeric argument raises run-time error 1004: Method 'Application.ActivateMicrosoftApp' of object '_Application' failed
but...
Executing the Application.ActivateMicrosoftApp method with an uninitialized variant variable launches Calculator (calc.exe)
Sub Test()
Dim a As Variant
Application.ActivateMicrosoftApp a
End Sub
Can anyone reproduce this behavior?