JSONRPC - "Unknown account" error?

[BE-CH]

I am trying to call a function named mint from my Smart Contract, but I get the error below.

The mint(uint256 _mintAmount) function is a public, payable function.

// Get the accounts
const accounts = await window.ethereum.request({ method: 'eth_requestAccounts' });
// Connect to JSONRPC provider
const provider = await new ethers.providers.JsonRpcProvider("https://polygon-rpc.com");
// Get the signer from the provider with address from MetaMask
const signer = newProvider.getSigner(accounts[0]);

// Create new contract with contract address, abi and signer
const contract = new ethers.Contract(process.env.NEXT_PUBLIC_CONTRACT_ADDRESS!, ABI, signer);

// Call the mint function from the smart contract with 1 as parameter. 
// The payable amount should be 0 as I only want to pay for gas.
const result = await contract.mint(BigNumber.from('1'), { value: BigNumber.from('0') });

This returns the error below:

Error: processing response error (body="{\"jsonrpc\":\"2.0\",\"id\":60,\"error\":{\"code\":-32000,\"message\":\"unknown account\"}}", error={"code":-32000}, requestBody="{\"method\":\"eth_sendTransaction\",\"params\":[{\"gas\":\"0x10c9a\",\"value\":\"0x0\",\"from\":\"0xef0923bb70a5b98811afca82267bfaf0bac987d8\",\"to\":\"0xfdb91f46919961bde261842185581353088f0e99\",\"data\":\"0xa0712d680000000000000000000000000000000000000000000000000000000000000001\"}],\"id\":60,\"jsonrpc\":\"2.0\"}", requestMethod="POST", url="https://polygon-rpc.com", code=SERVER_ERROR, version=web/5.5.1)

The body is just

{"jsonrpc":"2.0","id":60,"error":{"code":-32000,"message":"unknown account"}}

I know that the function is indeed being called, because when I try from another address that is not the owner of the contract, then I get an error saying that the address is not whitelisted (a requirement I implemented in the smart contract) as it is supposed to.

Does anyone know why I get this "Unknwon account" error? Is it related to the signer and JSONRPC?

[ricmoo]

I'm not sure where newProvider is coming from, but you need to get the Signer from the provider that controls the Signer; you likely want newProvider = new ethers.providers.Web3Provider(window.ethereum) to get the Signer from.

Let me know if that works. :)

[BE-CH]

Sorry for the late reply! Yes, that worked. ;)