TL;DR: How do you replace an existing save file on Pokemon Emerald VC (3DS), with a hacked Pokemon Emerald ROM on VBA? & vice versa? Also, did it matter that I didn't "patch" the GBA ROM? [Context]: Basically, I ran Gameshark codes on the Visual Boy Advance emulator so that I could hack Pokemon Emerald, which wasn't really possible for the 3DS VC. Even if it was, Codebreaker required a Master Code, and PKSM was a lot easier to use to hack DS/3DS Pokemon games. I thought that by hacking the GBA game on PC, I could easily transfer the save file to my 3DS VC and case-closed. [Transferring SAV file from 3DS VC to Hacked VBA (PC)]: I read a bunch of outdated and a few newer threads regarding this topic, and I decided to install decrypt9 so that I could create a backup for my 3DS VC and dump it onto my PC's desktop as a gbavc.sav. When I was successful at doing that, I downloaded VBA. Then, I downloaded a Pokemon Emerald GBA ROM from Vimm's Lair. Once I booted up the GBA ROM on VBA, I played through it until I could save the game; and then I reset the emulator. Immediately, I opened the "gbavc.sav" and imported it from my desktop, as a "Battery File" after I loaded the game again. A message popped up, "Importing a snapshot.." and I clicked "OK." A white screen came forth, and I reset the emulator again. Before the game loaded, this message displayed, "The save file has been erased due to corruption or damage." Finally, I had to start a brand new game and get all those shiny pokemon via Gameshark codes again. [Transferring Hacked SAV file from VBA (PC) to 3DS VC]: While I was hacking the GBA ROM on VBA again, I looked for more solutions to transfer the SAV file from VBA to my 3DS VC. I then inserted the GBA ROM into HxD, a hex editing program, and I was able to put the '00' as required in a guide. Furthermore, after hex editing, I transferred the SAV from VBA onto my 3DS VC (The Link to "PATCH pokemons roms and roms hacks" didn't work, so I skipped that). I renamed the SAV file, from VBA, to gbavc.sav and replaced the one existing (The save for my 3DS VC) on the files9 folder, which was located on the root of the 3DS SD Card. After that, I booted up my 3DS and ran Pokemon Emerald VC one last time, and then powered off the device to open Decrypt9. I went to: synandoption -> miscellaneous -> gba save import. Then, I rebooted it again and opened Pokemon Emerald, but nothing changed at all. In-fact my game was running the exact same way before the injection, so nothing got corrupted thankfully.