damn! yesterday I had this issue. I deleted all conversations and it is working then. after going through this thread and the comments in bug description, this bug is hard to reproduce.

in my case this happened for the first time. as far as i remember this happened to me, when the messages application is open and I received message alert on status bar and I clicked on the alert and found that message window is blank

I'm going to reproduce by sending multiple messages when messages app is open. lets see!