Metamask-extension: JsonRpcEngine error: response has no error or result for request getting pending block data.

[Pedro-vk]

To Reproduce
Steps to reproduce the behaviour:

1. Request the pending block.
2. The error is thrown and the console shows:

inpage.js:1 MetaMask - RPC Error: Error: JsonRpcEngine - response has no error or result for request:
{
  "jsonrpc": "2.0",
  "id": 3279580878,
  "method": "eth_getBlockByNumber",
  "params": [
    "pending",
    false
  ],
  "origin": "127.0.0.1"
}

Expected behaviour
Return pending block data without errors.

Browser details (please complete the following information):

• OS: Ubuntu 16.04
• Browser: Chrome
• MetaMask Version: 4.14.0
• Old UI or New / Beta UI? New UI

[tmashuang]

Seems to be happening for all methods that has the pending parameter.

[bdresser]

thanks for reporting @Pedro-vk - should be fixed by https://github.com/MetaMask/metamask-extension/pull/5510.