Why does the app sometimes say I can’t transfer Circles tokens (CRC)?
If you can’t send CRC to someone, make sure the person you are sending tokens to has trusted you. If they don’t trust you, and you don’t share “transitive trust connections'' (meaning: you trust other people who trust this person), you can’t send them Circles tokens.
It might also be the case that you have reached the trust limit (see below) between you and the recipient.