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

bool(false) object(DateTimeZone)#2905 (2) { ["timezone_type"]=> int(3) ["timezone"]=> string(13) "Europe/Zurich" }
Fatal error: Uncaught Error: Call to a member function format() on bool in /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-content/plugins/amr-ical-events-list/includes/amr-ical-events-list-main.php:2115 Stack trace: #0 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-content/plugins/amr-ical-events-list/includes/amr-ical-events-list-main.php(2304): amr_GET_params(Array) #1 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/shortcodes.php(434): amr_do_largecal_shortcode(Array, '', 'largecalendar') #2 [internal function]: do_shortcode_tag(Array) #3 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/shortcodes.php(273): preg_replace_callback('/\\[(\\[?)(largec...', 'do_shortcode_ta...', '[largecalendar ...') #4 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-content/themes/Divi/includes/builder/class-et-builder-element.php(3122): do_shortcode('[largecalendar ...') #5 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/shortcodes.php(434): ET_Builder_Element->_render(Array, '[largecalendar ...', 'et_pb_code') #6 [internal function]: do_shortcode_tag(Array) #7 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/shortcodes.php(273): preg_replace_callback('/\\[(\\[?)(largec...', 'do_shortcode_ta...', '[et_pb_text _bu...') #8 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-content/themes/Divi/includes/builder/main-structure-elements.php(3784): do_shortcode('[et_pb_text _bu...') #9 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-content/themes/Divi/includes/builder/class-et-builder-element.php(3441): ET_Builder_Column->render(Array, '[et_pb_text _bu...', 'et_pb_column', '', '', '', '', '') #10 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/shortcodes.php(434): ET_Builder_Element->_render(Array, '[et_pb_text _bu...', 'et_pb_column') #11 [internal function]: do_shortcode_tag(Array) #12 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/shortcodes.php(273): preg_replace_callback('/\\[(\\[?)(largec...', 'do_shortcode_ta...', '[et_pb_column t...') #13 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-content/themes/Divi/includes/builder/main-structure-elements.php(2274): do_shortcode('[et_pb_column t...') #14 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-content/themes/Divi/includes/builder/class-et-builder-element.php(3441): ET_Builder_Row->render(Array, '[et_pb_column t...', 'et_pb_row', '', '', '', '', '') #15 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/shortcodes.php(434): ET_Builder_Element->_render(Array, '[et_pb_column t...', 'et_pb_row') #16 [internal function]: do_shortcode_tag(Array) #17 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/shortcodes.php(273): preg_replace_callback('/\\[(\\[?)(largec...', 'do_shortcode_ta...', '[et_pb_row admi...') #18 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-content/themes/Divi/includes/builder/main-structure-elements.php(1606): do_shortcode('[et_pb_row admi...') #19 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-content/themes/Divi/includes/builder/class-et-builder-element.php(3441): ET_Builder_Section->render(Array, '[et_pb_row admi...', 'et_pb_section', '', '', '', '', '') #20 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/shortcodes.php(434): ET_Builder_Element->_render(Array, '[et_pb_row admi...', 'et_pb_section') #21 [internal function]: do_shortcode_tag(Array) #22 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/shortcodes.php(273): preg_replace_callback('/\\[(\\[?)(largec...', 'do_shortcode_ta...', '<div class="et-...') #23 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/class-wp-hook.php(324): do_shortcode('<div class="et-...') #24 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/plugin.php(205): WP_Hook->apply_filters('<div class="et-...', Array) #25 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/post-template.php(256): apply_filters('the_content', '[et_pb_section ...') #26 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-content/themes/Divi/page.php(46): the_content() #27 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-includes/template-loader.php(106): include('/home/clients/4...') #28 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-blog-header.php(19): require_once('/home/clients/4...') #29 /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/index.php(17): require('/home/clients/4...') #30 {main} thrown in /home/clients/4dc4e4a9f96581f789df633c17d2bef6/zpg_neu/wp-content/plugins/amr-ical-events-list/includes/amr-ical-events-list-main.php on line 2115