In case anyone was interested, I successfully used SaveDataFiler on the CFW to extract the save from the card1 Luigi's Mansion cartridge,but I couldn't restore it to the .cia version on Gateway emunand, it always gave a "Failure" message. Haven't tried doing it as a card2 .3ds rom, not sure it'll help.
Please help me! I have the same error. I've successfully installed DevMenu on CFW but when install SaveDataFilter and execute it then I get SD Card extracted error... What I need to do? I'm desperated...
Thanks in advice.