I think createAccount is not working well with remote access.
I try to make a new test accout using application.php and then result:
Reason is empty and the account was not created (even when all data was ok).Sorry, the registration failed!
Reason:
But if I use the same data in your local : http://remote.fsairlines.net/v1/application.php then work well
So I guess is something about permission to remote access.