"100 is an invalid custom form" error when trying to purchase with credit card

Question

The client reported they receive this error when trying to purchase with a credit card:

"100 is an invalid custom form"

Checked the form they are using, and it is the same one that they are using in SiteBuilder now, it works correctly on the live site. The site we are working on is SCS.

Answer 1

Make sure the form is set as active and preferred.