Cannot export privateKey data

[vanpd-0859]

    Web3.default = Web3(infura: .ropsten)
    let mnemonicsString = "shop inhale clutch young found cherry beauty enforce early ramp grunt pact voice front light trash shed jar giraffe snow misery radio number draw"
    let mnemonics = try! Mnemonics(mnemonicsString)
    let keystore = try! BIP32Keystore(mnemonics: mnemonics)
    Web3.default.keystoreManager = KeystoreManager([keystore])
    let privateKey = try! keystore.UNSAFE_getPrivateKeyData(password: "", account: keystore.addresses[0])

Fatal error: 'try!' expression unexpectedly raised an error: web3swift.AbstractKeystoreError.encryptionError("Failed to decrypt a keystore")