What happens if someone serves out of turn or we forget to change ends?

Under Law 2.14:

• Wrong server or receiver: play stops as soon as the error is discovered and resumes with the correct server and receiver for the score reached, following the order set at the start of the match (and, in doubles, the serving order chosen for that game).
• Wrong ends: play stops as soon as the error is discovered and the players move to the ends they should be at for the score reached.
• In every case, all points scored before the error was found still count. Nothing is replayed.