"Error: invalid address" for dapp, works on geth (Ganache)

Question

I have a contract that creates another contract in a function. I am testing the contract using Ganache. When calling this function using geth, it works fine. But when calling it using my dapp (yeoman, gulp, bower, etc.) it gives me "Error: invalid address" via the browser console.

I have copy and pasted the logic from my dapp into geth and it works as expected on geth, and the Ganache UI shows the transaction.

The following is the code:

web3 = new Web3(new Web3.providers.HttpProvider("HTTP://127.0.0.1:7545"));

web3.eth.defaultAccount = web3.eth.accounts[0];

var myContract = web3.eth.contract([abi left out for readability]);    
var contractAddress = '0xae01c97dc970ad45f7be5d23ba72ae24640e90b1';
var contract = myContract.at(contractAddress);

function sendPurchaseTrade() {
    contract.makePurchaseTrade('0x427d25b7c0B71C1944df51765c55Bea1961e0a44', {value: 200000, gas: 3000000});
}

The respective HTML page has a button with onclick="sendPurchaseTrade();".

Non state changing calls to the contract work with the dapp.

Any ideas as to why the exact same code will work on geth but not in my dapp?

Answer 1

The function containing the contract transaction had to have the web3.eth.default = web3.eth.accounts[0] statement inside of it.