Quote Originally Posted by Redspan View Post
How do I do this? turning off the setting that includes the transaction parameters to your redirect URL(s)
I'm guessing that that's a setting in your ePDQ account on their site.
Or, again guessing, maybe it's a setting in your ePDQ module in your Zen Cart admin?

Zen Cart's security system doesn't like long parameters in URLs, since that's often what hackers use when probing sites for vulnerabilities. It could be that the SHASIGN=hashhashhashhashhashhashhashhashhashhashhashhashhashhash is throwing it.