Got the same error today. When will we see a fix?
All In One Event Calendar has been disabled due to an error:
The specified file "agenda-widget-form.php" doesn't exist.
exception 'Ai1ec_Exception' with message 'The specified file "agenda-widget-form.php" doesn't exist.' in /path.../httpd.www/wordpress/wp-content/plugins/all-in-one-event-calendar/lib/theme/loader.php:294
Stack trace:
#0 /path.../httpd.www/wordpress/wp-content/plugins/all-in-one-event-calendar/app/view/calendar/widget.php(114): Ai1ec_Theme_Loader->get_file('agenda-widget-f...', Array)
#1 /path.../httpd.www/wordpress/wp-includes/widgets.php(270): Ai1ec_View_Admin_Widget->form(Array)
#2 [internal function]: WP_Widget->form_callback(Array)
#3 /path.../httpd.www/wordpress/wp-admin/includes/widgets.php(209): call_user_func_array(Array, Array)
#4 [internal function]: wp_widget_control(Array, Array)
#5 /path.../httpd.www/wordpress/wp-admin/includes/widgets.php(45): call_user_func_array('wp_widget_contr...', Array)
#6 /path.../httpd.www/wordpress/wp-admin/widgets.php(341): wp_list_widgets()
#7 {main}
