UOAA Discussion Board

I tried to send a pm by clicking on the pm icon next to a post, but when I click submit (after composing my message), the text of my message disappears and text appears in red above the compose box, stating "The requested users to be added do not exist." What am I doing wrong? (The username of the person to whom I want to send the pm is above the text box. I checked the list of users and this person's name is in the list.)

After receiving a pm in reply to my question from the Site Admin, and after several more unsuccessful attempts to send a pm, I figured out what I was doing wrong. I was writing my message in the "To" box, instead of the message text box, which is below the "To" box. Once I wrote my message in the correct box, my pm's went through without problems. It is easy to mistake the "To" box for the message box because the "To" box is relatively spacious and the user name of the the person to whom the pm is addressed is already printed above the "To" box.