One user got this message out of the blue. We recently switched to WVD (Windows Virtual Desktop) if that matters.
I was able to open the database myself without any issue, other than it opening slowly.

This is the code:
Private Sub butNew_Click()
On Error GoTo ER
' Openargs N indicates 'New', in this case myRole is not passed
DoCmd.OpenForm "frmCases", , , , , , "N"
Exit Sub
ER:
MsgBox Err.Description, , "butNew_Click"
End Sub