Customers Recieving Error Code on Renewal
It sounds like an Auth.net password issue. Check this out from their support page on the 103 error: 


  This error is generated when your Authorize.Net account is in
  Password-Required Mode and you are not sending a valid Transaction Key
  or hash fingerprint with your transaction request.


https://support.authorize.net/authkb/index%3Fpage%3Dcontent%26id%3DA852