1.51 is too new to work on the emulators in retropie but you can rebuild an older romset from 1.51 so that it will work. The program you will use is called clrmamepro. See this page on how to do that:

https://github.com/retropie/RetroPie-Setup/wiki/Managing-ROMs

Near the bottom shows which romsets work with each emulator and has links to the database files you’ll need to rebuild the sets: courtesy of floob. There is a video tutorial linked on that page as well for convenience.