SendTransaction - error with 'loadChainIdFromNetwork' vs 'custom chain id'

Hello,

I have been using the following code to "send Transaction" without any problem, but with an 'old' version of Flutter (1.xx) :

#######

Future setEthClient() async {
Client httpClient;
Web3Client ethClient;
httpClient = Client();
ethClient = Web3Client(
"https://rinkeby.infura.io/v3/afc2….”, //note : partially erased here for privacy concerns :)
httpClient);
return ethClient;
}

Future cacheSend(
String receiverRequest,
String myPrivateKeyAddress_String,
Web3Client ethClient,
DeployedContract contract,
String functionName,
List args,
EthereumAddress myAddress,
int maxGasAmount) async {

final credentials =
    await ethClient.credentialsFromPrivateKey(myPrivateKeyAddress_String);
final ownAddress = await credentials.extractAddress();

final ethFunction = contract.function(functionName);

final transactionHash = await ethClient.sendTransaction(
  credentials,
  Transaction.callContract(
      contract: contract,
      function: ethFunction,
      parameters: args,
      from: myAddress,
      maxGas: maxGasAmount),
  fetchChainIdFromNetworkId: true,
);

return transactionHash;

}
}

#######

Since I have upgraded to Flutter 2.xx , I have the following error message :

#######
[ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: Invalid argument(s): You can't specify loadChainIdFromNetwork and specify a custom chain id!
#######

Changing "fetchChainIdFromNetworkId : true" to "fetchChainIdFromNetworkId : false", I get another error message
#######
Unhandled Exception: RPCError: got code -32000 with msg "invalid sender"
#######

I use web3dart: ^2.1.4.

After trying to find out some answer with Google & Co, without any result, I am asking for your help.
Thanks in advance.

Regards,
S.

You need to explicitly set the chainId to null when you set featchChainIdFromNetworkId: true, by default chainId is set to 1.
Here is the line of code that is throwing

web3dart/lib/src/core/transaction_signer.dart

Line 19 in af4c3fb

if (loadChainIdFromNetwork && chainId != null) {

client.sendTransaction(
        EthPrivateKey.fromHex(privateKey),
        transaction,
        chainId: null,
        fetchChainIdFromNetworkId: true,
      );

Hello,

Perfect ! All transactions 'send' working :)
Thanks a lot.

Regards,
S.