If a user reports that they cannot edit a payment form because the edit form meta boxes are not shown.
At some point, that user account had hidden the Payment Form meta boxes. WP Simple Pay has a function that removes the “Screen Options” tab on the WP Simple Pay form editing screens. This prevents the Screen Options from being re-enabled as usual.
We have created a plugin that will reset the screen options, form edit fields, etc. These should be displayed again after installing the plugin linked below:
https://www.dropbox.com/s/4rgpepcqn5fz4nh/wp-simple-pay-reset-screen-options.php.zip?dl=1
Original issue: https://github.com/awesomemotive/wp-simple-pay-pro/issues/2102