I saw that the card formatting issue was already closed, but I did run into errors as well. Just commenting with a simple fix that worked for me that allowed me to kept the icons:
Fix: After pasting in the card yaml, move these 3 lines from the bottom of the card to the top. Then you can save it.
show_header_toggle: false
title: Samba Backup
type: entities
I’m honestly not sure why that fixed it. If I paste a brand new card with the 3 lines at the top - I receive the same errors and moving them back to the bottom allowed me to save it without errors.