I use dash testnet send privateSend Transaction also find this problem
./dash-cli -testnet sendtoaddress ydbfLPQ4iFGvgeGjrAineJdczthNgjxRKA 4.5 "sendtoaddress example" "Nemo From Example.com" false false true
error code: -4
error message:
Unable to locate enough PrivateSend denominated...