As part of OS X Mountain Lion, Apple is completely revamping their instant messenger client. Instead of the classic iChat program, the new OS is going to ship with a program called Messages. There’s currently a beta of Messages out for OS X Lion, and the initial impressions of it have been rather mixed. I personally am sticking with Adium for my instant messenger needs, but I still have Messages installed on my desktop so that I can send iMessages without having to get my phone out.
There is one problem however. In the current version of the Messages beta, the program will occasionally show a badge on it’s dock icon indicating that there’s one unread message. If you pull the app up however, there won’t be anything new waiting for you. While this isn’t a huge bug, it’s still rather irritating for OCD types who like having all their badge icons cleared out.
To remove the one unread message badge, open up the Terminal application, it’s located in your Application folder’s Utility folder. In that window, type, “killall Dock” without quotes. That should clear everything up for the time being. After entering that command, you can exit the Terminal application.