This isn't a major bug, just a minor annoyance.
The problem is that the Skada chat window, if you don't have Skada installed, is still shown in the right side display window. The only way I could turn it off was to go into the \default\infopanels folder and rename the file nUI_InfoPanel_Skada.lua.
Skada sounds like a nice combat log addon, but since I only rarely do raids I don't see much point in having it installed.