sberman on "[Plugin: Visual Form Builder] Security check: referral does not match this site."

WordPress 4.0.1 (started the error. Just updated to 4.1.1.
Visual Form Builder Version 2.8.1
StudioPress Executive Pro Theme

Client states this message "Security check: referral does not match this site." pops up when submitting the forms:
http://actionshred.com/quote/
http://actionshred.com/schedule/

And the forms then do not go through, nor do they show the form thank you landing pages.

https://wordpress.org/plugins/visual-form-builder/