Can't set LogonPageLightSelectionEnabled to True

Hello,

There're two Exchange servers - Exch1 and Exch2. I'm applying some customization to their Owa directories, for example, setting LogonPageLightSelectionEnabled  property to $true.

Exch1: - all works perfect:

Exch2:"... parameter cannot be found..."

Silly question: how this parameter "cannot be found" if it can be easily displayed?

Regards,

Michael