I play Emerald about 3 - 4 times, then when I turn it on, it says, "The game file has been deleted due to coruption or damage". Is that a bug?
All I did was save it, go to bed, sleep and play it when I woke up!
Sorry, Your Game is gone. After you play GBA games alot, they delete their own data. You wont be able to get that data back. The game might not be able to save anymore, either that, or Time Events such as berries growing, will never happen again....
This means that your game is either damaged in some way, or as Swampert said, the internal battery is not up to stuff. However, some games you are still able to save and play the game (usually without time) although the game data can delete itself at any moment.