Hello all. I noticed some people are having trouble getting online to work with Gateway so I've created a tutorial on how to do it. Someone suggested a sticky thread for all things online so if a mod could sticky this that would be awesome. A few things to note before starting. 1. If you want to play online you have to start the game over. With card 2 games (Pokemon X/Y and Animal Crossing New Leaf) using a rom that has already been played will give you an error. You have to do this with a brand new rom. With every other game, you can use the rom you already have but it will not use your save. Instead it will replace it with a new one. There is no way around this as far as I know. 2. I would make a back up of your Micro SD and SD card just in case. And now the tutorial Things you will need. A physical retail copy of any 3ds game. It doesn't have to be a game with online, any game will work. I used the header from my copy of Zelda: Ocarina of Time on Pokemon X/Y and Animal Crossing New Leaf and it worked perfectly Gateway ROM Patcher http://scene.releases.free.fr/tools/download.php?dl=GRP_v1.2 That's all =D Dumping your retail game (Your SD card must be big enough to hold the game you are dumping or else you will get an error) 1. Insert your retail game cartridge into your 3ds 2. Go to the Gateway menu and select "Backup 3DS Game Cartridge" 3. Press [START] to dump Game. Wait for it to finish 4. Press [A] To Exit 5. Turn off the 3ds and Take out the SD Card 6. Open the SD card on your computer. There will be a .3ds file where your .sav files are. This is the rom that was created from your retail game. Move this to your desktop. Extracting the header 7. Open Gateway ROM Patcher and click "Load ROM" 8. Open the .3ds file on your desktop 9. Click "Export header to file" and save the .bin file to your desktop Injecting the header into your rom 10. Make a copy of the game you want to play online and put it on your desktop 11. In Gateway ROM Patcher click "Load ROM" again and this time open the rom you want to play online 13. Click "Import header from file" and open the .bin file on your desktop 14. A message will pop up saying "This Chip ID seems not adapted to your ROM size. Can I suggest a better value?". Click yes. (If the Chip ID is the same for both roms this message won't pop up and you can just skip to step 16) 15. Copy the info from Cartridge ID on top to the Cartridge ID box below. The Chip ID box should have already been filled automatically when you pressed yes before. Click "Apply". 16. Close out of Gateway ROM Patcher 17. Change the file extension on the rom from .3ds to .3dz. Put the rom on your Micro SD, load it normally, and play online. The Manufacturer remains the same however and it might be the wrong one. But try it first and if you can go online after doing these steps, that must be the cause. That's all there is to it. If you have any questions let me know and I will try to answer them as best I can. I hope this helps at least some of you. Good luck to all!