Please see here the capture from the error log:
PHP message: PHP Fatal error: Uncaught Error: Call to a member function check_yn() on bool in /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-content/plugins/eventON/includes/class-single-event.php:164nStack trace:n#0 /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-content/plugins/eventON/includes/class-single-event.php(92):
the full capture below. i am not sure if this is a JS error from any other plugin?
[Sun Jun 14 11:38:52.115368 2020] [proxy_fcgi:error] [pid 20689:tid 139859561801472] [client 90.146.247.14:56718] AH01071: Got error ‘PHP message: PHP Fatal error: Uncaught Error: Call to a member function check_yn() on bool in /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-content/plugins/eventON/includes/class-single-event.php:164nStack trace:n#0 /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-content/plugins/eventON/includes/class-single-event.php(92): evo_sinevent->page_content()n#1 /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-includes/class-wp-hook.php(287): evo_sinevent->after_content(”)n#2 /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(”, Array)n#3 /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-includes/plugin.php(478): WP_Hook->do_action(Array)n#4 /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-content/themes/wplms/eventon/single-ajde_events.php(166): do_action(‘eventon_single_…’)n#5 /var/www/vhosts/neuro-training.academy/dev.neuro…’, referer: https://dev.neuro-training.academy/wp-admin/edit.php?post_type=ajde_events
[Sun Jun 14 11:39:39.200615 2020] [proxy_fcgi:error] [pid 25028:tid 139859570194176] [client 90.146.247.14:57026] AH01071: Got error ‘PHP message: PHP Notice: Undefined offset: 0 in /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-content/plugins/wplms-eventon/includes/init.php on line 299’, referer: https://dev.neuro-training.academy/wp-admin/post.php?post=17313&action=edit&classic-editor
[Sun Jun 14 11:39:43.476837 2020] [proxy_fcgi:error] [pid 25028:tid 139859570194176] [client 90.146.247.14:57026] AH01071: Got error ‘PHP message: PHP Notice: Undefined offset: 0 in /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-content/plugins/wplms-eventon/includes/init.php on line 299PHP message: PHP Fatal error: Uncaught Error: Call to a member function check_yn() on bool in /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-content/plugins/eventON/includes/class-single-event.php:164nStack trace:n#0 /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-content/plugins/eventON/includes/class-single-event.php(92): evo_sinevent->page_content()n#1 /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-includes/class-wp-hook.php(287): evo_sinevent->after_content(”)n#2 /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(”, Array)n#3 /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-includes/plugin.php(478): WP_Hook->do_action(Array)n#4 /var/www/vhosts/neuro-training.academy/dev.neuro-training.academy/wp-content/themes/wplms/eventon/single-ajde_events.php(166): do_action(‘eventon_single_…’)n#5 /var/www/vhosts/neuro-training.academy/dev.neuro…’, referer: https://dev.neuro-training.academy/wp-admin/post.php?post=17313&action=edit&classic-editor