Searching on the internet for that particular error message has identified a number of possible causes, but it seems to do with stripe not receiving all of the applicable information to be able to provide back a positive response.

So, that would lead me to look at the process of developing the current site and how it is different from a brand new new unaltered site. Further would encourage reviewing the credentials entered to support the operation and verifying that those for test were only used for test and those for production only for production, if there is some difference between the two conditions


I mean, one individual reported that their problem was fixed by including a call to implement jQuery on a page. While I doubt that would specifically be the problem using a default install with the built-in (unmodified) templates, it's important to first check the basics (again?). :)