I gave up on ever finding a fix for this as a kid years ago but after 20 or so years I tried again with the youtube guides about enabling real-time and saving .sav or .sgms as Flash128. Then tried pkhex to try changing the time to before the 22nd or 88th hour cos I read a suggestion On gamefaqs beating wallace any hour after 22 and before 88 results in a glitched corrupt save. I think my .sav has been corrupted even before Elite4 though I can't remember..is there any way to fix the .sav ? It's right before facing Wallace though.
Pokemon_-_Emerald.sav