I did a little digging and it seems others have this problem as well.
http://techforums.nintendo.com/message/141239
The link above clarifies it all. The reason being you are using a 2nd SD Card. What happens is the 1st SD Card is linked to the game, so if you use a 2nd SD card to make a new game, the 1st SD card will receive this error.
I am not sure if this is the problem you are having, but if this is the case, there is no way to salvage the first file.
EDIT: http://techforums.nintendo.com/message/113612 ( I know this is for X and Y, but I am sure the same logic applies).
I did a bit more looking around, and another reason this could occur is because your save file isn't the same version as the game. For example, if the game is version 1.2, but the save data is version 1.1, this error will occur. Like above, there is no fix for it.
EDIT 2: http://www.gamefaqs.com/boards/696959-po...260?page=1 (Once again, X and Y, but I am assuming same logic)
In the 2nd comment of the 2nd page, the the game will only load the most recent save date of the game. So if you backed up your game, but it is not the most recent save, the game will remember, and will give you this error. Also, if you turn off the system will the game is saving, yea you guessed it.
http://techforums.nintendo.com/message/141239
The link above clarifies it all. The reason being you are using a 2nd SD Card. What happens is the 1st SD Card is linked to the game, so if you use a 2nd SD card to make a new game, the 1st SD card will receive this error.
I am not sure if this is the problem you are having, but if this is the case, there is no way to salvage the first file.
EDIT: http://techforums.nintendo.com/message/113612 ( I know this is for X and Y, but I am sure the same logic applies).
I did a bit more looking around, and another reason this could occur is because your save file isn't the same version as the game. For example, if the game is version 1.2, but the save data is version 1.1, this error will occur. Like above, there is no fix for it.
EDIT 2: http://www.gamefaqs.com/boards/696959-po...260?page=1 (Once again, X and Y, but I am assuming same logic)
In the 2nd comment of the 2nd page, the the game will only load the most recent save date of the game. So if you backed up your game, but it is not the most recent save, the game will remember, and will give you this error. Also, if you turn off the system will the game is saving, yea you guessed it.