Hi,
I have created a user group where the users are allowed to send and receive messages.
In the next step I add this users to my contact list.
Then I tried to send them a message:
1. I choose the tab in backend "messages > contacts" (as attached - demo server was not reachable, so its my german backend)
2. I select one or more checkboxes.
3. I click onto "Send a message to all selected contacts"
4. I get a new, empty message form - with an empty field of recipients.

And this empty field, I guess, should not be. I guess, there should be the selected names in it. I don't know it because I have not used it before. First try now.