I have 4 userforms

From the main menu - click on button1

Private Sub CommandButton1_Click()
Headcount.Show
MainMenu.Hide
End Sub

Works Fine!
====
from the Headcount form, if you click on the MainMenu button

Private Sub CommandButton25_Click()
Headcount.Hide
MainMenu.Show
End Sub

I get Run-time Error: '400'
"Form already displayed, can't show modally"

In Properties, ShowModal = True

I'm stuck - I've also tried Load and Unload and cannot find a way around this.

Thanks for any help!