Pokemon white 2 crashes and deletion of save file.

[Fenicemaster]

Hello, i have a white 2 rom and i have completed almost everything, i was doing the big white tree and then i saved at the second town in the game (venturia in italian). I was curious about something and decided to enter the entralik, nothing out of the ordinary, but when i tried to access the missions of the tree, it crashed and when i tried to get back it sayed file deleted because of damaged files, but when i soft reset with start+select+L+R it doesn't delete those files... I had never had a problem with savestates and saving or clock things but now i fear i cannot reset white and go change the keys whitout having my game deleted... Please help, thanks anyway