Why do I get error message saying "Cannot open 1Password data"

Aha! I inaccurately assumed you were referring to some feature in 1P that would allow me to exclude it from backups. I understand that I can do it in CCC. However, if I do that and ever need to recover my files and apps from my CCC clone backup, 1P would be missing. In that scenario (as unlikely as it is), I would just download and install a new copy of 1P and link it to my 1P data, right?