Help: My 3DS can't read my SD card.

My 3DS won't read my SD card (the Toshiba that comes with the 3DS). I've looked all over the Internet for a solution but I haven't found one that works for me. I've unlocked it, blew on it, re-formatted it, and tried an SD card -- one from my camera. Still won't work. The error message I've been getting is

"Could not detect an SD Card. The software on the SD Card could not be displayed."

Any suggestions? Thanks in advance. :D
[ Am I in the right place? :/ ]

Have you accidentally locked your SD card? If you slide the white tab on the SD card, you can lock the SD card, preventing editing.

If the tab has fallen off, you'll need to get a new SD card.

Nope. The error didn't say anything about write-protection, and I'm sure my SD card is unlocked. I've even tried taping down the tab as a few have suggested before. By the way, extra games/apps/software from the eShop like Pokedex and Virtual Console are gone from the main screen. :/

If you've tried a alternate card, it might be something wrong with the SD reader.

And ofc the extra stuff is gone, it was stored on the memory card.

Thanks, but I don't have any other SD card besides the one from my camera. Tried to put that in, and still got the same error. Does that have to do with the fact that it's from my camera and not an empty card? Also another thing to add -- I plugged my SD card into my computer and it works fine; I did a scan on the card for errors and there were no problems. This might be a 3DS system problem, but I don't know for sure.

First off I'd follow what TF said and try updating it, sometimes companies will restrict their products so you're forced to update to the latest firmware. Failing that try and see if there's anything inside the SD card slot that might've gotten caught in there or has broken off inside it that could be stopping the 3DS from reading the SD card.

Thanks, but again that doesn't seem to be the problem. My 3DS is up-to-date, and I also tried an empty micro-sd card (with adapter and formatted to FAT32).I've tried looking in the sd-card slot, but I couldn't really see anything that was broken, but I can't be sure that nothing is broken. At this point, I'm sure it's a 3DS problem and not the SD card. ._. Is there anything else I can do besides getting it repaired? That's gonna be my last resort.

Have you tried blowing in the socket where the SD card goes?
It's an Occam's razor fix to it but really, this fixes more electronic problems then it should (Remember the old N64 and before days?)

Do you have a spare SD?
If so, see if that one works. If it does, it's the SD card. If it doesn't it could be the 3DS. or two faulty SDs