This error can occur if the fee includes a long description. The character limit settings are controlled by PayPal and not the WordPress form itself. In order to resolve this error, we recommend either keeping the fee description under 64 characters or add a 'Total' field on the form and associate the PayPal fee with this field using the following steps:
  1. Log into the site dashboard.
  2. Navigate to Forms > Edit the form in question.
  3. Expand the Pricing Fields > Drag and drop the 'Total' field onto the form.
  4. Save.
  5. In the form editor, select the Settings tab > PayPal.
  6. Click the Edit hyperlink for the PayPal settings.
  7. From the Payment Amount drop down, select From Total.
  8. Click Update Settings to save.