CrissieLuckey on "[Plugin: Contact Form] Error Message Always Displays When I Add the Form"

Here's what I see each time I add a contact form to a page:

Warning: strpos() expects parameter 1 to be string, array given in /home4/crissie/public_html/wp-includes/shortcodes.php on line 193

That error message appears in both the WP page editor and on the actual page that displays to the public. WHY?

See the page at:

https://wordpress.org/plugins/contact-form-plugin/