DraStic

This is the problem. I tried to reload an in-game save and save again but it continued to freeze while saving so without a reason I deleted all in-game saves.
An other thing, when I try to save in game some question marks appear in the date.

2.2.1.2a but I started playing in older versions and I used some cheats to obtain first generation pokemons.
I don't think the cause of the problem is the use of cheats anyway.

I didn't use the in-game save for a while and now when I try to save in game or try to disable c-gear communication the game freezes.
But the real problem for me is the black screen when the gym leader skyla asks you if you're ready to fly to the Reversal Mountain, I thought the problem could be ...