<p>Yup, it seems like the validation for your script fails, usually, when that happens you'll get this error <code>ValidationTagMismatch (IsValid True)</code> (and you got it).</p>
<p>There is probably something wrong with either datum or redeemer.</p>

CC BY-SA 4.0
2021-12-30T08:33:30.093Z
2021-12-30T08:33:30.093Z
pyropy
<p>I am running one smart contract with the Nami Wallet but I get this error:</p>
<pre><code>&quot;&quot;transaction submit error ShelleyTxValidationError ShelleyBasedEraAlonzo (ApplyTxError [UtxowFailure (WrappedShelleyEraFailure (UtxoFailure (UtxosFailure (ValidationTagMismatch (IsValid True) (FailedUnexpectedly [PlutusFailure \&quot;\\nThe 3 arg plutus script (PlutusScript ScriptHash \\\&quot;4b8980baf5b09f3573f26e100df813dd24a619d78188b9d56471e51f\\\&quot;) fails.\\nCekError An error has occurred:  User error:\\nThe provided Plutus code called 'error'.\\nThe data is: Constr 0 [B \\\&quot;\\\\220\\\\166\\\\ETXW\\\\DC2\\\\241d\\\\219/\\\\153\\\\199\\\\DC4\\\\EOT\\\\211\\\\146\\\\DC1]+\\\\221\\\\227f\\\\251\\\\190\\\\&amp;5\\\\154\\\\224\\\\US\\\\GS\\\&quot;,I 5000000,B \\\&quot;\\\\233&gt;\\\\198 \\\\150\\\\&amp;1Q\\\\ETB\\\\DC3\\\\184\\\\&amp;2\\\\229\\\\&amp;&quot;
</code></pre>
<p>It is from the Martify Repo <a href="https://github.com/MartifyLabs/martify.contracts" rel="nofollow noreferrer">https://github.com/MartifyLabs/martify.contracts</a> in the buy endpoint. I just wanted to be sure.. The error comes from plutus contract not validating right? since there are not datum or another related error in the transaction that i can read. It is related to this post <a href="https://cardano.stackexchange.com/questions/4057/cardano-cli-error-when-submitting-transaction">Cardano-cli error when submitting transaction</a> when they get the same error in the cancel endpoint.</p>
<p>My doubt comes from the fact that the console does not logs the error messages provided in the on-Chain code:</p>
<pre><code>{-# INLINABLE mkBuyValidator #-}
mkBuyValidator :: PubKeyHash -&gt; NFTSale -&gt; SaleAction -&gt; ScriptContext -&gt; Bool
mkBuyValidator pkh nfts r ctx =
    case r of
        Buy    -&gt; traceIfFalse &quot;NFT not sent to buyer&quot; checkNFTOut &amp;&amp;
                  traceIfFalse &quot;Seller not paid&quot; checkSellerOut &amp;&amp;
                  traceIfFalse &quot;Fee not paid&quot; checkFee
        Update -&gt; traceIfFalse &quot;No rights to perform this action&quot; checkUser &amp;&amp;
                  traceIfFalse &quot;Modified datum other than price&quot; checkDatum &amp;&amp;
                  traceIfFalse &quot;NFT left the script&quot; checkContinuingNFT
        Close  -&gt; traceIfFalse &quot;No rights to perform this action&quot; checkUser &amp;&amp;
                  traceIfFalse &quot;Close output invalid&quot; checkCloseOut
</code></pre>
<p>So before start debugging i would like to know i am looking at the right place, I assume this traces are not shown because of the maximum size of the printed error that Nami allows, am I right?</p>

<smart-contract><nami-wallet><cardano-serialization-lib>
Error submiting Smart Contract with Nami, What does this error means?
# Error submiting Smart Contract with Nami, What does this error means?

(Asked by: username_0 on 2021-12-30)

I am running one smart contract with the Nami Wallet but I get this error:

```
""transaction submit error ShelleyTxValidationError ShelleyBasedEraAlonzo (ApplyTxError [UtxowFailure (WrappedShelleyEraFailure (UtxoFailure (UtxosFailure (ValidationTagMismatch (IsValid True) (FailedUnexpectedly [PlutusFailure \"\\nThe 3 arg plutus script (PlutusScript ScriptHash \\\"4b8980baf5b09f3573f26e100df813dd24a619d78188b9d56471e51f\\\") fails.\\nCekError An error has occurred:  User error:\\nThe provided Plutus code called 'error'.\\nThe data is: Constr 0 [B \\\"\\\\220\\\\166\\\\ETXW\\\\DC2\\\\241d\\\\219/\\\\153\\\\199\\\\DC4\\\\EOT\\\\211\\\\146\\\\DC1]+\\\\221\\\\227f\\\\251\\\\190\\\\&5\\\\154\\\\224\\\\US\\\\GS\\\",I 5000000,B \\\"\\\\233>\\\\198 \\\\150\\\\&1Q\\\\ETB\\\\DC3\\\\184\\\\&2\\\\229\\\\&"

```

It is from the Martify Repo <https://github.com/MartifyLabs/martify.contracts> in the buy endpoint. I just wanted to be sure.. The error comes from plutus contract not validating right? since there are not datum or another related error in the transaction that i can read. It is related to this post [Cardano-cli error when submitting transaction](https://cardano.stackexchange.com/questions/4057/cardano-cli-error-when-submitting-transaction) when they get the same error in the cancel endpoint.

My doubt comes from the fact that the console does not logs the error messages provided in the on-Chain code:

```
{-# INLINABLE mkBuyValidator #-}
mkBuyValidator :: PubKeyHash -> NFTSale -> SaleAction -> ScriptContext -> Bool
mkBuyValidator pkh nfts r ctx =
    case r of
        Buy    -> traceIfFalse "NFT not sent to buyer" checkNFTOut &&
                  traceIfFalse "Seller not paid" checkSellerOut &&
                  traceIfFalse "Fee not paid" checkFee
        Update -> traceIfFalse "No rights to perform this action" checkUser &&
                  traceIfFalse "Modified datum other than price" checkDatum &&
                  traceIfFalse "NFT left the script" checkContinuingNFT
        Close  -> traceIfFalse "No rights to perform this action" checkUser &&
                  traceIfFalse "Close output invalid" checkCloseOut

```

So before start debugging i would like to know i am looking at the right place, I assume this traces are not shown because of the maximum size of the printed error that Nami allows, am I right?

**Tags:** smart-contract, nami-wallet, cardano-serialization-lib


---

## 1 answers

### Answer by username_1 on 2021-12-30. Score: 2 | Accepted answer

Yup, it seems like the validation for your script fails, usually, when that happens you'll get this error `ValidationTagMismatch (IsValid True)` (and you got it).

There is probably something wrong with either datum or redeemer.


---

