Why are my Authorize.net transactions failing with improperly formatted results?
There several settings in the Authorize.net console which you can set and some of these can cause problems with processing transactions. One such setting is called “Encapsulating character”. In the Authorize.net merchant interface you can set this from your Settings & Profiles > Direct Response > Encapsulating Character. You will want to make sure that this is set to blank. If you have any other character entered there then that could cause processing issues.