Error in preview - there was a problem with your submission. no order id available, cannot create a new payment

When I preview the form I receive an error notice stating that “there was a problem with your submission. no order id available, cannot create a new payment.” I’ve tried various things like clearing cache, renaming the PayPal checkout feed, etc. but haven’t eliminated the message yet.

I’ve noticed that this happens when I hit enter on the User Defined Price field. For example, enter1. and hit enter key. The 1. changes to 1.00 which is correct and then the error message pops up at the top of the form.