Error: The operation couldn’t be completed. Illegal byte sequence

Recieve this error when I try to compress the following folder:

User/Library/Biome/streams/restricted/Mailcontent/local/*.*

I stumbled aross this as my Acronis b/u software started failing after the upgrade to Ventura 13. I found if I excluded the above folder my backups started working. No idea why. I think the two are linked but have no idea. I am curious why I get the Illegal byte sequence error?