Pokemon Crystal Version

It's probably the battery (it's almost kaput).

If you have a corrupted save file, it most likely occured when you turned off the game during the "Saving. Don't turn off the power." message.

I had the same problem! Hopefully you have a GBA SP or my solution won't work...
I'm not sure how late in the game you can stop but I plugged in my adapter and left the game on all the time. I defeated the Elite Four when I saved and turned it off. A week later I turned my SP on and the file wasn't corrupted! Hope this works for you too...

When you dont play try not to move the game in the slot too much then it will corrupt it happend to me several of times.

Ok, I remember one time it said corrupted save file, what does it mean? It means this file is corrupted and you must start a new game.

Just to let you know, if you start a new game and after you save, the game will either say new game after or it will have you your save file. A little thing you must know, if you saved evertime but it always says new game, that mean the internal battery must be replaced since it's dead

Other than that, just restart a new file and go on with it.

It could also mean that the Gameboy battery died while you were saving.

Same happend 2 me.Try these:1.Save wice before turning off your GBC.2.Try 2 play as often as possible.3.Dont remove your cartrdge untill you beat the game.4.put your gbc were you know it wont fall5.If you have a BRO OR SIS KEEP IT OUT OF THERE REACH.6.lastly save often.Hope this helped.