Same error message and same problem as other here. Over the past 24 hours we have tried: multiple browsers, clearing cache and cookies,  resending the invoice, creating a new invoice...all resulting in the same vague error message suggesting to try again or come back later.  I have spoken at length with customer support in several departments including merchant services. At no time has anyone in customer support mentioned what the problem may be or that this is a known issue as mentioned in this thread. They simply say "It should work if you resend the invoice and try processing the payment again".  Quickbooks Moderator, please do not reply to my message with an apology. This isn't a hurt feelings issue for which an apology would be appropriate, this is a technical issue for which a technical solution would be appropriate. If you have the solution then please reply. If you don't have the solution then please spare me the apology line. Thanks.