Read only contract calls reverting with CALL_EXCEPTION

[steddyman]

I have been successfully running Ethers to automate various trades against the PancakeSwap rotuer and various token contracts for about 2 weeks successfully.

Since Saturday, I have started to receive all sort of random errors, and also tx.wait sometimes never returns A common one I am seeing is the balanceOf function is reverting. It is being read using the following code:

const _balanceBefore = ethers.BigNumber.from(await _tokenContract.balanceOf(wallet.address))

and the sort of error I am receiving includes:

UnhandledPromiseRejectionWarning: Error: call revert exception (method="balanceOf(address)", errorArgs=null, errorName=null, errorSignature=null, reason=null, code=CALL_EXCEPTION, version=abi/5.4.0)

The only thing I know has changed for sure in that time is Mac OSX updated itself at the weekend to Mac OS Big Sur 11.5. But I don't think this is the issue as I've moved the scripts over to my Windows machine and run them under WSL2 (Ubuntu) and I am seeing the same errors.

The scripts have not changed in all this time. I have tried using a new QuickNode and I am seeing the same problems on the new node. I've tried deleting the node_modules directory and doing an npm install again. Nothing I do seems to be getting anywhere.

Has anyone got any ideas what this could be? It is driving me nuts. The node is running Geth 1.10.2 and I am connecting using the JsonRpcProvider.

[zemse]

You would get Error: call revert exception whenever the eth_call fails. I assume you do not change your code at all, so it works some time and it doesn't work some time, so I feel that there can be some network issue. I've seen exact behaviour when running scripts on my machine with a remote node and a temporary network outage. If you think a network issue can be possible, you can try running scripts on some aws ec2 whcih definitely does not have any network issue. Plus this comes at an added benefit that you don't have to keep your laptop/computer on, and bot on the server runs 24x7 if you prefer that.

[ghost]

I have same issue and sometimes it works and sometimes not. Using hardhat the local network and tried also with mainnet fork

Error: call revert exception (method="getTokenAmount(uint256)", errorArgs=null, errorName=null, errorSignature=null, reason=null, code=CALL_EXCEPTION, version=abi/5.4.0)
    at Logger.makeError (index.ts:213)
    at Logger.throwError (index.ts:225)
    at Interface.decodeFunctionResult (interface.ts:425)
    at Contract.<anonymous> (index.ts:332)
    at Generator.next (<anonymous>)
    at fulfilled (index.ts:2)

[steddyman]

I am using QuickNode, and they are saying this issue in an issue with Binance Smart Chain in general and the heavy load on the network. I switched to a public node and it had been working fine, but just looks to have also gone offline.

[ghost]

The revert exception means that the contract does not exist. I can see the instance on my browser in the console and then if I try to call the function it does not work. I tried also with instance.interface.encodedFunctionData('function', [data]) and it execute at least the function

[zemse]

Hey @melonecrypto, can you try doing provider.getCode(contractAddress) just to confirm that contract exist or not (if not then probably you're using a different network for deploying and calling function). Also you can get the call revert exception if the contract is present but the method does not present (such dev error mostly happens when we copy-paste the contract address incorrectly).

[ghost]

Well, I could solve my problem. I was calling the contract twice and the second call the params were empty.