Provider Error when unwrap()

If I unwrap() a value that I read from the contract, it generates the error below. It looks like provider error. I using as my rpc provider. Do you guys know about this error?

thread 'testnet_tests::mint::mint' panicked at 'called `Result::unwrap()` on an `Err` value: ProviderError("Response errors; Unknown field \"fuelBlockSpend\" on type \"Message\".")', tests/testnet_tests/