Good you that you've managed to solved it!
And no before I posted that suggestion I hadn't seen anywhere in your post that you already tried it/wasn't clear to me (or else I wouldn't have suggested it), as you only said that you tried running the game through Hans & that it worked for AC:NL, but not AC:HHD. I meant with AC:NL not being relevant was that you asked about another game at first & mentioned using HANS a totally different homebrew & hax compared to the Luma CFW + Locale switcher app. Suddenly the focus was all about the other game "AC:NL" that was working on Hans instead of AC:HHD which was the game you asked help for I didn't want to argue either. I was actually just trying to be considerate & help you properly as things started to become confusing for me! Which why I suggested things & used words like "might be corrupted" instead of your game is corrupted you should try reinstalling & see if it works.If I had know reinstalling hadn't worked I'd ask more ofcourse.
Also not everyone tries simple things as reinstalling etc. Please keep in mind that there're also people that aren't that advanced users, so they'll ask about questions you might consider silly as they're still trying to learn it's alot of info afterall & simple things might turn out not to be as simple as thought.
Another thing is that the games are different as in that they also require different firmware to work, so that also could've been an issue if you were running the game on like fw 9.2. You also didn't give any info regarding your fw, system etc. Do you get my point a bit now?
So here's a tip
Next time you need help, please also mention your system firmware, everything you tried etc. It can help solve things faster & prevent miscommunications like we had + others that might've this issue later could also properly see a possible solution! And after you solved it, it'd be nice to edit the opening post with the solution that helped for you. I think I'll try doing the same, it saves alot of reading/searching through posts.^^
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Installing cfw on your 3ds/ hacking, modding your 3ds is not really illegal either, but downloading/pirating commercial games you haven't bought /backuped yourself legally is. Talking about how/where to get them (pm's not allowed either), telling others to pirate, links to commercial .cia/3ds/any other files that're protected under copyright etc. is forbidden on this forum.
I think plenty of people got bans, because they confused talking about legal backups with illegally obtained games. In your case you're supposed to be talking about a game you purchased legally. So, please be careful in future I wouldn't mention where you got the game on this forum, unless you got it legally ofcourse. (I'd also edit my 1st post a bit if I were you)
Freeshop is now an "illegal" homebrew app & it was DCMA'ed because it contained copyrighted Nintendo code + made it possible for people to illegally obtain games etc. I think I read the creators made it unavailable after that DCMA, hence my reaction.
P.S I decided not to PM you because it's better if it's in the open to prevent other people making the same mistake. It happens pretty often, because a lot of people don't read the full agreements etc. When they sign up.