start Date could not be converted to date object.Check date and global timezone.

bool(false) object(DateTimeZone)#3114 (2) { ["timezone_type"]=> int(3) ["timezone"]=> string(12) "Europe/Paris" }
Fatal error: Uncaught TypeError: date_modify(): Argument #1 ($object) must be of type DateTime, bool given in /home/rscdsparkd/www/wp-content/plugins/amr-ical-events-list/includes/amr-ical-events-list-main.php:2092 Stack trace: #0 /home/rscdsparkd/www/wp-content/plugins/amr-ical-events-list/includes/amr-ical-events-list-main.php(2092): date_modify(false, '-146400000 days') #1 /home/rscdsparkd/www/wp-content/plugins/amr-ical-events-list/includes/amr-ical-events-list-main.php(2210): amr_GET_params(Array) #2 /home/rscdsparkd/www/wp-includes/shortcodes.php(434): amr_do_ical_shortcode(Array, '', 'iCal') #3 [internal function]: do_shortcode_tag(Array) #4 /home/rscdsparkd/www/wp-includes/shortcodes.php(273): preg_replace_callback('/\\[(\\[?)(iCal)(...', 'do_shortcode_ta...', '[iCal https://w...') #5 /home/rscdsparkd/www/wp-includes/class-wp-hook.php(324): do_shortcode('[iCal https://w...') #6 /home/rscdsparkd/www/wp-includes/plugin.php(205): WP_Hook->apply_filters('[iCal https://w...', Array) #7 /home/rscdsparkd/www/wp-includes/post-template.php(256): apply_filters('the_content', '[iCal https://w...') #8 /home/rscdsparkd/www/wp-content/themes/spacious/content-page.php(26): the_content() #9 /home/rscdsparkd/www/wp-includes/template.php(812): require('/home/rscdspark...') #10 /home/rscdsparkd/www/wp-includes/template.php(745): load_template('/home/rscdspark...', false, Array) #11 /home/rscdsparkd/www/wp-includes/general-template.php(206): locate_template(Array, true, false, Array) #12 /home/rscdsparkd/www/wp-content/themes/spacious/page.php(17): get_template_part('content', 'page') #13 /home/rscdsparkd/www/wp-includes/template-loader.php(106): include('/home/rscdspark...') #14 /home/rscdsparkd/www/wp-blog-header.php(19): require_once('/home/rscdspark...') #15 /home/rscdsparkd/www/index.php(17): require('/home/rscdspark...') #16 {main} thrown in /home/rscdsparkd/www/wp-content/plugins/amr-ical-events-list/includes/amr-ical-events-list-main.php on line 2092