I let the user select which payment processor to use. Since I made this change, PayPal standard has stopped communicating correctly with CIVICRM.
When someone puts a payment through a webform w/civicrm intergration, they go to PayPal standard and payment is taken, but when the form attempts to return the user back to the website it comes up with error shown in the screenshot. The payment stays as pending in CIVI.
The link for the error page is https://www.vegansociety.com/civicrm/contribute/transact?_qf_ThankYou_display=1&qfKey=
CIVICRM 4.6.33 - Drupal 7.
Any ideas? Thanks, Andy