It is an application setting, so you will need to make sure that theirs is set too.
You can check it with this code, and tell the users what to do if it is not.
Function VBAIsTrusted() As Boolean Dim mpVBC As Object Dim mpAlerts As Boolean mpAlerts = Application.DisplayAlerts Application.DisplayAlerts = False On Error Resume Next Set mpVBC = ThisWorkbook.VBProject.VBComponents.Item(1) On Error GoTo 0 Application.DisplayAlerts = mpAlerts VBAIsTrusted = Not mpVBC Is Nothing End Function