[NSFW] PHP Fatal Error caused by class-wp-statistics-schedule.php

Hello,

I had switched on DEBUG and this resulted in a load of errors caused by WP_STATISTICS. The errors all occur in class-wp-statistics-schedule.php. See errors below.

Please advise.

[02-Dec-2020 11:23:05 UTC] PHP Fatal error: Uncaught Error: Class ‘WP_STATISTICS\Purge’ not found in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/wp-statistics/includes/class-wp-statistics-schedule.php:187
Stack trace:
#0 /home/public/sites/www.happykitesurfschool.nl/wp-includes/class-wp-hook.php(287): WP_STATISTICS\Schedule->dbmaint_event()
#1 /home/public/sites/www.happykitesurfschool.nl/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(”, Array)
#2 /home/public/sites/www.happykitesurfschool.nl/wp-includes/plugin.php(544): WP_Hook->do_action(Array)
#3 /home/public/sites/www.happykitesurfschool.nl/wp-cron.php(138): do_action_ref_array(‘wp_statistics_d…’, Array)
#4 {main}
thrown in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/wp-statistics/includes/class-wp-statistics-schedule.php on line 187
[02-Dec-2020 11:44:37 UTC] PHP Notice: Undefined index: hide_time_start_hour in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 68
[02-Dec-2020 11:44:37 UTC] PHP Notice: Undefined index: hide_time_start_minutes in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 69
[02-Dec-2020 11:44:37 UTC] PHP Notice: Undefined index: hide_time_end_hour in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 70
[02-Dec-2020 11:44:37 UTC] PHP Notice: Undefined index: hide_time_end_minutes in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 71
[02-Dec-2020 11:48:47 UTC] PHP Notice: Undefined index: hide_time_start_hour in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 68
[02-Dec-2020 11:48:47 UTC] PHP Notice: Undefined index: hide_time_start_minutes in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 69
[02-Dec-2020 11:48:47 UTC] PHP Notice: Undefined index: hide_time_end_hour in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 70
[02-Dec-2020 11:48:47 UTC] PHP Notice: Undefined index: hide_time_end_minutes in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 71
[02-Dec-2020 11:58:52 UTC] PHP Notice: Undefined index: hide_time_start_hour in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 68
[02-Dec-2020 11:58:52 UTC] PHP Notice: Undefined index: hide_time_start_minutes in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 69
[02-Dec-2020 11:58:52 UTC] PHP Notice: Undefined index: hide_time_end_hour in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 70
[02-Dec-2020 11:58:52 UTC] PHP Notice: Undefined index: hide_time_end_minutes in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 71
[02-Dec-2020 12:09:17 UTC] PHP Notice: Undefined index: hide_time_start_hour in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 68
[02-Dec-2020 12:09:17 UTC] PHP Notice: Undefined index: hide_time_start_minutes in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 69
[02-Dec-2020 12:09:17 UTC] PHP Notice: Undefined index: hide_time_end_hour in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 70
[02-Dec-2020 12:09:17 UTC] PHP Notice: Undefined index: hide_time_end_minutes in /home/public/sites/www.happykitesurfschool.nl/wp-content/plugins/ht-click/inc/woocommerce/class-ht-click-woo-style.php on line 71
[02-Dec-