Fatal error when editing user

When editing a user I get an error at the bottom of the page

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In the server error log I see the following

AH01071: Got error ‘PHP message: PHP Fatal error: Uncaught Error: Call to undefined function mc_kses_elements() in /var/www/wordpress/wp-content/plugins/my-tickets/my-tickets.php:793\nStack trace:\n#0 /var/www/wordpress/wp-includes/class-wp-hook.php(303): mt_user_profile()\n#1 /var/www/wordpress/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters()\n#2 /var/www/wordpress/wp-includes/plugin.php(470): WP_Hook->do_action()\n#3 /var/www/wordpress/wp-admin/user-edit.php(821): do_action()\n#4 {main}\n thrown in /var/www/wordpress/wp-content/plugins/my-tickets/my-tickets.php on line 793’, referer: https://www.stjohnsshirley.org.uk/wp-admin/user-edit.php?user_id=97&wp_http_referer=%2Fwp-admin%2Fusers.php%3Fs%3Dbecky%26action%3D-1%26new_role%26ure_add_role%26ure_revoke_role%26primary_role%3Dshop_manager%26paged%3D1%26action2%3D-1%26new_role2%26ure_add_role_2%26ure_revoke_role_2
[Thu Oct 14 15:31:20.478272 2021] [proxy_fcgi:error] [pid 981:tid 139885163816704] [client 141.101.105.26:12604] AH01071: Got error ‘PHP message: PHP Fatal error: Uncaught Error: Call to undefined function mc_kses_elements() in /var/www/wordpress/wp-content/plugins/my-tickets/my-tickets.php:793\nStack trace:\n#0 /var/www/wordpress/wp-includes/class-wp-hook.php(303): mt_user_profile()\n#1 /var/www/wordpress/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters()\n#2 /var/www/wordpress/wp-includes/plugin.php(470): WP_Hook->do_action()\n#3 /var/www/wordpress/wp-admin/user-edit.php(821): do_action()\n#4 {main}\n thrown in /var/www/wordpress/wp-content/plugins/my-tickets/my-tickets.php on line 793’, referer: https://www.stjohnsshirley.org.uk/wp-admin/users.php?s=becky&action=-1&new_role&ure_add_role&ure_revoke_role&primary_role=shop_manager&paged=1&action2=-1&new_role2&ure_add_role_2&ure_revoke_role_2

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