The Plutus script evaluation failed [Homework Week 02]

Question

I'm a have problem unlocking the smart contracts of the homework of week 02.

The Plutus code:

{-# LANGUAGE DataKinds           #-}
{-# LANGUAGE ImportQualifiedPost #-}
{-# LANGUAGE NoImplicitPrelude   #-}
{-# LANGUAGE TemplateHaskell     #-}

module Homework1 where

import qualified Plutus.V2.Ledger.Api as PlutusV2
import           PlutusTx             (compile)
import qualified PlutusTx.Prelude     (Bool, (&&),BuiltinData, True)
import           Utilities            (wrap, writeValidatorToFile, writeDataToFile)
import           Prelude              (IO)

---------------------------------------------------------------------------------------------------
----------------------------------- ON-CHAIN / VALIDATOR ------------------------------------------

{-# INLINABLE mkValidator #-}
-- This should validate if and only if the two Booleans in the redeemer are True!
mkValidator :: () -> (PlutusTx.Prelude.Bool, PlutusTx.Prelude.Bool) -> PlutusV2.ScriptContext -> PlutusTx.Prelude.Bool
mkValidator _ (x,y) _ = (x && y) 

wrappedVal :: PlutusTx.Prelude.BuiltinData -> PlutusTx.Prelude.BuiltinData -> PlutusTx.Prelude.BuiltinData -> ()
wrappedVal = wrap mkValidator

validator :: PlutusV2.Validator
validator = PlutusV2.mkValidatorScript $$(PlutusTx.compile [|| wrappedVal ||])

saveHM :: IO ()
saveHM = writeValidatorToFile "./Homework1.plutus" validator

The cardano-cli script:

cardano-cli transaction build \
    --babbage-era \
    --testnet-magic 2 \
    --tx-in "$txin" \
    --tx-in-script-file "$assets/Homework1.plutus" \
    --tx-in-inline-datum-present \
    --tx-in-redeemer-file "$assets/redeemer-success.json" \
    --tx-in-collateral "$collateral" \
    --change-address "$(cat "$keypath/$name.addr")" \
    --protocol-params-file "$pp" \
    --out-file "$body" 
    
# Sign the transaction
cardano-cli transaction sign \
    --tx-body-file "$body" \
    --signing-key-file "$keypath/$name.skey" \
    --testnet-magic 2 \
    --out-file "$tx"

# Submit the transaction
cardano-cli transaction submit \
    --testnet-magic 2 \
    --tx-file "$tx"

And the redeemer that I generated using the writeDataToFile function of the utilities module. Both values are the serialization of the tuple (True,True)so the smart contract should be unlocking the funds:

{"constructor":0,"fields":[{"constructor":1,"fields":[]},{"constructor":1,"fields":[]}]}

The above raises me this problem when building the transanction:

Command failed: transaction build  Error: The following scripts have execution 
failures:
the script for transaction input 0 (in the order of the TxIds) failed with:
The Plutus script evaluation failed: An error has occurred:  User error:
The machine terminated because of an error, either from a built-in function or from an explicit use of 'error'.
Caused by: [
  (builtin unConstrData)
  (con data #a24b636f6e7374727563746f7200466669656c647380)
]
Script debugging logs:

Command failed: transaction submit  Error: Error while submitting tx: ShelleyTxValidationError ShelleyBasedEraBabbage (ApplyTxError [UtxowFailure (UtxoFailure (AlonzoInBabbageUtxoPredFailure (ValueNotConservedUTxO (MaryValue 0 (fromList [])) (MaryValue 4799493069 (fromList []))))),UtxowFailure (UtxoFailure (AlonzoInBabbageUtxoPredFailure (BadInputsUTxO (fromList [TxIn (TxId {_unTxId = SafeHash "18af21838e2ae7b1f078caca222b5f1c992aeb08e38ccbade289458bc97e8225"}) (TxIx 1)]))))])

Thank you for your responses in forehand!

Answer 1

BadInputsUTxO means the input UTxO doesn't exist. It may have existed previosuly and has since been spent. Query the ledger state for current UTxOs and make sure to update your $txin accordingly.