So yeah, looks like we got an early X/Y Lumiose kind of glitch if you save outside a building (like a center but ofc we know Mauville is a building itself but you should know what I mean) your game will crash and you cannot reload your file much like the glitch from Lumiose City before the patch. Just thought I'd share this to you all to avoid saving outside the Pokemon center there so none of you guys suffer from this glitch and we can hope they can patch it soon like GF did in X/Y.