Hello!
I have configured change pass web part to work with forms based auth by disabling windows authentication on my web app (this is only left method? i want to use two methods of authentication but cannot change web part authentication mode, selected windows auth by default, forms auth is grayed) and receive error - The Web Part Is Configured to Work With membership provider, but the current membership provider is TrustedProvider. And When i select FormsBased auth it displays Membership Provider field - empty.