Posted 27 March 2012 - 01:24 PM
I, too, use manual processing. I've never seen the error that you did. I guess you have to start with what has changed between when you were getting the normal number of order and when they declined. Program update? A change on the server side? Is Credit Card still showing a green Active state? Are the transactions that do come through using the same card type as you used when you had the error?
With so many things to consider, I would troubleshoot as best as you can but then put in a ticket with temporary ftp credentials so that tech support can see what they can find.