The following are a couple common errors that you may run into if you haven’t configured your Authorize.Net (SIM) account and payment pages correctly:
(13) The merchant login ID or password is invalid or the account is inactive. - This error occurs when either your login Id or transaction key are invalid. Please refer to the section on Configuring Authorize.net above and make sure that you have obtained the proper login Id and transaction key.
(14) The referrer, relay response or receipt link URL is invalid. - This error occurs when you have not entered a response/relay URL into Authorize.net, or the response/relay URL