I am trying to run a few examples of deploying a smart contract to testnet using the cardano-cli. I am running version 1.33.0 for both the cardano-cli and cardano-node. The example I am using is from https://github.com/input-output-hk/cardano-node/tree/master/plutus-example (plutus-example).

I can successfully transfer tADA to the script addresses. However, I cannot unlock the funds that are locked at the script addresses. The error message is below - from the little that I find on internet, it looks like an issue with the redeemer, but I can't figure out how to correct. Can anybody help? My understanding is that both datum and redeemer must both equal a specific value for validation to work (I changed 42 to 1970).

Error message (for cardano-node/plutus-example) -> 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 provided Plutus code called 'error'. Caused by: [ (builtin unConstrData) (con data #1907b2) ] Script debugging logs:

Code for plutus-example.hs and CustomDatumRedeemerGuess.hs are only slightly modified compared to the repo (no change in logic, only in some file naming).

The cardano-cli commands I use are as follows ->

cardano-cli address build
--payment-script-file custom.plutus
--out-file custom-script.addr

cardano-cli transaction hash-script-data --script-data-value 1970 export scriptdatumhash=7619130e301e1b52e1c333c96d8489fba07ea98eeec3327f719a03d2c713302f

cardano-cli query protocol-parameters --$testnet --out-file protocol.json

cardano-cli transaction build
--change-address $address1
--tx-in 4c7c3e12d3ed18241520a8c95a7f68855a1e17af933e207918f65a66bd02c49e#0
--tx-out $(cat custom-script.addr)+10000000
--tx-out-datum-hash $scriptdatumhash
--protocol-params-file protocol.json
--out-file tx-script.build

cardano-cli transaction sign
--tx-body-file tx-script.build
--signing-key-file ../nft/payment.skey
--out-file tx-script.signed

cardano-cli transaction submit --$testnet --tx-file tx-script.signed

Up until here, everything works great and I can transfer funds to the script address.

However, running the following transaction build command fails with the error message above ->

cardano-cli transaction build
--tx-in 29f0adfb6ff1ba9b4cb9117b3678cf84532314a1b82a29a6991dfcc38e37d4c6#1
--tx-in-script-file custom.plutus
--tx-in-datum-value 1970
--tx-in-redeemer-value 1970
--tx-in-collateral 29f0adfb6ff1ba9b4cb9117b3678cf84532314a1b82a29a6991dfcc38e37d4c6#0
--change-address $address3
--protocol-params-file protocol.json
--out-file test-alonzo.tx

Can anyone help me? Thanks in advance, Simon

1 Answer 1


The error output points to error in the actual script. It seems the BuiltIn data is unreadable:

The Plutus script evaluation failed: An error has occurred:  User error: 
The provided Plutus code called 'error'. Caused by: [ (builtin 
unConstrData) (con data #1907b2)
  • Thanks, I'll try and investigate that
    – simon
    Jan 30, 2022 at 16:47

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