Braintree with Wordpress not working with CiviEvent
Figured it out. For some reason, the braintree keys were not being loaded at the time before it started to post to Braintree. In Braintree.php I added the following

 if (empty(Braintree_Configuration::environment())) {
  $environment = ($this-&gt;_mode == "test" ? 'sandbox' : 'production');
  Braintree_Configuration::environment($environment);
}

if (empty(Braintree_Configuration::merchantId())) {
  Braintree_Configuration::merchantId($this-&gt;_paymentProcessor["user_name"]);
}

if (empty(Braintree_Configuration::publicKey())) {
  Braintree_Configuration::publicKey($this-&gt;_paymentProcessor["password"]);
}

if (empty(Braintree_Configuration::privateKey())) {
  Braintree_Configuration::privateKey($this-&gt;_paymentProcessor["signature"]);
}


Right before the following:

try {
  $result = Braintree_Transaction::sale($requestArray);
} catch (Exception $e) {
  return self::error("Oops! Looks like there was problem. Payment Response: " . $e-&gt;getMessage());
}


And it worked. I'm not entirely sure why the values weren't being loaded initially but this will do!