Seems like the spoilers button is broken. Though, it's weird, because I never touched the spoilers button. I'll open up my console log later today (it's 6:00 AM right now)

Also, the only other theme that have broken "download 3DS/Wii U themes" that I'm aware of is the themes by Louiskovoski, which still point to the now dead DSHack. I'll fix those once my Internet comes online, though do you mind telling me if you find some that don't work.

Speaking of spoilers, yeah, they're used for the wrong reasons. They shouldn't be used to hide links and stuff like that. While the spoilers should be fixed, I'm also going to edit some of the depot entries that use them because you shouldn't be using them like that.

Also, would you mind linking me to threads that you found spoilers in them for download links?

I have fixed the bug.

To explain more in depth, it was relating to a change I have previously made to the engine known as TimeAgo.
Lately, I've been trying to make things lightweight for users with old devices (well, old devices that support HTTPS. I'm not going to be supporting Dial-Up device :P), and there was one thing I was trying really hard to remove: The usage of jquery. It makes everything really laggy on older devices and it's one of those things that need to be removed. I've started the process by making TimeAgo use the no-jquery fork, which required me to remove the following bit of code:

$(document).ready(
    function () { 
        $(".spoilerbutton").click(toggleSpoiler);
        jQuery.timeago.settings.strings = {
            prefixAgo: '',
            prefixFromNow: '',
            suffixAgo: 'ago',
            suffixFromNow: 'from now',
            seconds: '%d seconds',
            minute: "%d minute",
            minutes: "%d minutes",
            hour: "%d hour",
            hours: "%d hours",
            day: "%d day",
            days: "%d days",
            month: "%d month",
            months: "%d months",
            year: "%d year",
            years: "%d years"
        };
        //jQuery.timeago.settings.cutoff = 1000;
        $('time.timeago').timeago();
    }
);

If you can read the code properly, you would notice the use of $(".spoilerbutton").click(toggleSpoiler);, which allows spoilers to be toggled. Since I didn't read the code correctly (was studying for school finals), I thought the entire function was jquery timeago and just removed it. However, when looking through the ABXD repository, I've noticed my mistake and have fixed it.

Thankfully, the other changes on that day were all carefully done, so I guess it was one rotten egg.
However, since it's a change to a CSS or a JS file, you'll need to reload your cache. On android, go to settings, apps, (web browser), remove cache. On Windows, do CTRL + F5. I'm not sure the command to do so on a Mac, so MoonlightCapital will let you know.

I am sorry for this whole mess, and I hope nothing like this happens in the future.