I ended up just using the rsync command from my first post.

I didn’t expect it to work but, Everything seems to be back to normal now.

Although I didn’t know I could merely just reinstall the RetroPie manager.

Thanks @mitu!

@mitu Okay ,thanks for your help :)

i think it might be simpler to have your arcade rom folder on the server: https://github.com/RetroPie/RetroPie-Setup/wiki/Running-ROMs-from-a-Network-Share

this way, the mame .hi files themselves would be also on this server (see https://github.com/RetroPie/RetroPie-Setup/wiki/lr-mame2003#high-scores), so you would both be using the same individual files. i guess you wouldn't be able to log scores on the same game at the exact same time.