Bad News Does Not Improve with Age: how to know when to speak up

One of the key challenges of teamwork and leadership is when to bring up items of concern and when not to. Should you give the feedback, or let it go? Point out the problem you see (that no one else seems to), or “be supportive” (and see what happens)? One obviously cannot bring up every issue that might be a problem. But in my experience people tend not to address items that need to be brought up, rather than the other way around.