Macromind101

I've tried downloading different Platinum roms but none of them appear to be compatible with pkhex. It keeps saying the input file is too large. I've tried looking this up and I've seen from other threads that changing the file extension to .sav or .dsv may help but it didn't work for me. Any help would be appreciated! (Note that I do know previous threads for Platinum not working with pkhex exist but I again, I haven't had any luck following the suggestions on those threads)