I have this problem exactly. Everything is installed properly as best I can tell. I only get this error message which doesn't help diagnose the problem whatsoever. If anyone has a solve for this I would greatly appreciate it.
Thanks!
New install of OSC and using the built-in AIM method. Get "There has been an error processing your credit card" error. Please, anyone with suggestions let me know. We need this site to launch today if possible...