4.5.1 is really old and I don't think it's supported anymore - i.e. there are no more binary packages to download for the Raspbian version on which it was based. You may try installing reicast from source to get it back.

@gdhgdh Thanks so much for your contribution. You saved me from becoming crazy to make work this Waveshare product with my Rpi 3A+.
Just downloaded a few days ago the image, burned it and all worked fine.
Yesterday, I was cleaning the Waveshare folder on my hard disk (that was full of useless tryings, images, drivers etc.). Accidentally, I've deleted also your image and now, the link is no more avalaible.
This discussion in very old, but please, if you can hear me, coul you share the image again?
Thanks in advance!
p.s. Sorry for my english...