What happens if someone serves out of turn or from the wrong court, or we forget to change ends?

Under the BWF Laws of Badminton:

• Service court error (Law 12): serving or receiving out of turn, or from the wrong service court. When it's discovered, it's corrected while the shuttle is not in play, and the existing score stands. Points already played aren't replayed.
• Change of ends (Law 8.2): if you don't change ends when you should, change as soon as the mistake is discovered and the shuttle isn't in play. The existing score stands.