Topic: Smash Bros 3DS online doesn't work anymore

Guys, I'm having some trouble with my game and I hope you can help me out!

I play the game on a physical game card on a classic original 3DS, so re-downloading isn't an option. I have owned the game since launch, and everything has always worked fine. However, since a few weeks I can't play online anymore. Whenever I select online, it says it's exchanging data with the server, than the screen starts lagging like crazy, almost to the point of freezing for a little while (though the music is still fine, so I guess it's loading), then I get an error message that it can't connect and I get kicked back to the game's main menu.
It's not my internet connection, because apps like YouTube, Nintendo Anime Channel and the eShop work fine. Even the DLC Shop in Smash works without any trouble. The router is only like a few feet away from me, and in the Home menu, it says I have full conection. I have the most recent update for Smash installed.
I tried clearing my internet settings in the system settings and reconnecting, but it didn't work.

Does anyone know how to fix this? Please help!

I think I fixed it. I went to the eShop and ran the download fix program on the update. I still get a lot of connection errors when I select the mode once I'm online, but I can still find games after enough tries, and hey, I'm online.
While it may work somewhat now, as I said, there are still errors. Again, everything else is fine. Does anyone know how to fix this?

Never mind. I tried to play again just now, and it stopped working again. Please, is there someone out there that knows a solution?

Perhaps contact Nintendo support?

I will, but this sunday and monday is Pinksteren here in the Netherlands, which means everyone is free from school and work, so I guess that has to wait until Tuesday. I was hoping someone would know, so I would be able to play before then.

Admins, you can close this threat now. I fixed it.
I simply went into my system settings and deleted the additional data (not additional content or updates, just additional data). I believe I only lost my replays, everything else is still there, and the online works fine again.