Quote Originally Posted by lat9 View Post
@RWJ99, I'll need to look at this in the morning (I'm sure I'll have additional questions). My puzzlement is that I've got a client running one of the zc1.5.5 variants with OPC and the winchester_responsive template without issue.

One thing before I go for the day: How did you install the base Zen Cart?
New install using Filezilla and download from Zencart. Added the Winchester Responsive template. I can disable OPC and everything works fine and fails after clicking on Continue from the PayPal page.