Application error 1004 due to a drop down box.

I have this code I found and altered it for my use.
My requirement was to select every shape but a button linked to the macro and group them together since the number of shapes can change with what I select in my excel sheet (It creates a collated diagram).

Dim vShapesToExclude As Variant
Dim aShapesToSelect() As String
Dim oShape As Shape
Dim vMatchVal As Variant
Dim ShpCnt As Integer: ShpCnt = 0

vShapesToExclude = Array("Button 1")

ReDim aShapesToSelect(1 To ActiveSheet.Shapes.count)

For Each oShape In ActiveSheet.Shapes
    vMatchVal = Application.Match(oShape.Name, vShapesToExclude, 0)
    If IsError(vMatchVal) Then
        ShpCnt = ShpCnt + 1
        aShapesToSelect(ShpCnt) = oShape.Name
    End If
Next oShape

ActiveSheet.Shapes.Range(aShapesToSelect()).Select
ActiveSheet.Shapes.Range(aShapesToSelect()).Group

This works fine if I change nothing in the excel sheet but the moment I click on my drop down box, and I don't even need to change anything, it breaks giving me the classic 1004 error.

I had a look into what was causing this with "debug.print" on the "aShapesToSelect" array thinking maybe something was empty, instead I'm met with a log of "Drop down" instead of "textbox" causing the issues.

I have absolutely no idea what is causing the switch over and I can only get it working again if I recompile the code to "reset" the selection.

Any assistance is appreciated, thanks.

I'm guessing you're talking about a data validation dropdown? Try looping through the sheet's DrawingObjects collection instead.