Hypernova

yes. I did the ROM editing, the issue is it cant open the file anymore because of the size issue which i don't know how to resolve or why it could be happening now

I just followed this guide for modifying shiny rates, and now I get an error message when trying to open my ROM. The end of the guide tells you to use a specific Gengar to see if it worked, so I wanted to try that, but I can't seem to get it to work. Yesterday I was using PKHeX and it worked perfectly fine and the bak-files do still open (bak-files from PKHeX are 512KB and my ROM is somehow 262,144KB). I have the most recent PKHeX version. Any help would be appreciated.