Gas Estimation Failed error when scheduling Aion call

I am trying to understand the Aion scheduling system, so I tried their code example from here. Below is the code snippet: pragma solidity ^0.4.24; // interface Aion contract Aion { uint256 public serviceFee; function ScheduleCall(uint256 blocknumber, address to, uint256 value, uint256 gaslimit, uint256 gasprice, bytes data, bool schedType) public payable returns (uint,address); } //…