OK, now it's gone! I overwrote the .sav file as you said, exporting the file battery, and it opens on PKXDelta
It does not open on VBA, though. But that's not a problem, first I open pokemon crystal ROM, and then select "Continue game".
Thank you very much, you've got great patience for sure, explaining things to a noob like me
Can I write under this post if I'll have similar problems for the future?