Sending object array to variant works before August 2019 Windows update, but fails after update

Question

Running the subroutine RunMe works before August 2019 Windows update.

Running the subroutine RunMe fails after August 2019 Windows update. It reports the following error message: "Invalid procedure call or argument (Error 5)"

Public Sub RunMe()
  Dim wksTestArray() As Worksheet
  MsgBox SendArrayToFunction(wksTestArray())
End Sub

Public Function SendArrayToFunction(ByVal vntArray As Variant) As Boolean
  SendArrayToFunction = True
End Function

Please note: The error only occurs for an unallocated array.

It can be useful for a function to accept a Variant, which can be either an Array of values, or an Array of objects, for example, IsArrayAllocated is an example function where this would be required.

Is there a fix?

Answer 1

The update affects VB6, VBA (including all versions of Office) as well as VBScript!

Microsoft is currently looking into the issue: https://support.microsoft.com/en-us/help/4512488/windows-8-1-update-kb4512488 (look at the last row under the section entitled "Known issues in this update")

Update:

Microsoft just released a patch for this issue: https://support.microsoft.com/en-us/help/4517298/windows-8-1-update-kb4517298

Answer 2

To fix, change the ByVal to ByRef in the function:

Public Sub RunMe()
  Dim wksTestArray() As Worksheet
  MsgBox SendArrayToFunction(wksTestArray())
End Sub

Public Function SendArrayToFunction(ByRef vntArray As Variant) As Boolean
  SendArrayToFunction = True
End Function