Forms Won’t Delete

I’m working with forms and finding I am getting errors. I’ve tried clearing cache and I’ve tried to deactivate and deleted RSVPMaker and then rebooting and downloading and activating RSVPMaker and RSVP Volunteer Roles twice. However, when I go into RSVPMaker Settings, the RSVP Form tab, and try to create a reusable RSVP Form, the previous form names I’ve created are still there on the drop down. And when I try to create a form with the same name, I get the error:

“You attempted to edit an item that doesn’t exist. Perhaps it was deleted?”

wp_die()

Somehow these forms don’t delete when I un-activate and delete the RSVP Plugins. I’ve tried creating a new form name and still get errors. I still see their names under RSVP Form choices.

I am trying to work around it by giving my new form a new name. However, I am still getting errors:

Fatal error: Uncaught Error: Call to undefined function santize_text_field()
in /var/www/wp-content/plugins/rsvpmaker/rsvpmaker-form.php on line 103

Call stack:

customize_rsvp_form()
wp-includes/class-wp-hook.php:292
WP_Hook::apply_filters()
wp-includes/class-wp-hook.php:316
WP_Hook::do_action()
wp-includes/plugin.php:484
do_action()
wp-admin/admin.php:175
require_once()
wp-admin/edit.php:10

Any thoughts on this would be appreciated. For context, I’m trying to setup events for volunteer committee signup which have an annual term.