The latest update for the Xbox One may add a few useful new features, but it sounds like it adds a new bug, as well. Fortunately, Microsoft has an easy workaround.
Some users are reporting that the update gives them a black screen after the system turns on. Users on Reddit report that the result is a screen that flickers various shades of black, while users on the Xbox Forums report a similar issue.
Xbox Support tweeted earlier that they're aware of the problem, and advised an easy way to address it:
@jay_to_the_son We are aware, thank you! If it happens, please power cycle by holding power for 10 seconds. ^BB
-- Xbox Support (1-5) (@XboxSupport) February 17, 2014
Always nice when a problem that appears worrying has an easy workaround in the end. We've asked Microsoft if there's anything else users should know about the bug, and will update if we hear back.