In #861 it was pointed out that the Register link shows up at times that it shouldn't. I believe some work was done in #874 to try to rectify this. However, that seems to have had the unintentional side effect of now making it impossible to view puzzles in old events that you never "registered" for because they ran before the concept of registration existed.
Specifically, if you go back to Puzzlehunt 21 for example, the top bar just shows "Pregame puzzles", which links to the single player puzzle page, which is of course empty for that event. There's no way to Register, and no way to get to the Team puzzles page.
In #861 it was pointed out that the Register link shows up at times that it shouldn't. I believe some work was done in #874 to try to rectify this. However, that seems to have had the unintentional side effect of now making it impossible to view puzzles in old events that you never "registered" for because they ran before the concept of registration existed.
Specifically, if you go back to Puzzlehunt 21 for example, the top bar just shows "Pregame puzzles", which links to the single player puzzle page, which is of course empty for that event. There's no way to Register, and no way to get to the Team puzzles page.