Neustart Symposium header (2)

Fatal error: Uncaught Error: [] operator not supported for strings in /is/htdocs/wp13106097_OSXZ33YTWJ/www/online-kongresse.info/wp1/wp-content/plugins/pixelmate/include/pixelmate_includes.php:38 Stack trace: #0 /is/htdocs/wp13106097_OSXZ33YTWJ/www/online-kongresse.info/wp1/wp-includes/class-wp-hook.php(326): Pixelmate_includes->exclude_js_from_autoptimize('wp-includes/js/...') #1 /is/htdocs/wp13106097_OSXZ33YTWJ/www/online-kongresse.info/wp1/wp-includes/plugin.php(205): WP_Hook->apply_filters('wp-includes/js/...', Array) #2 /is/htdocs/wp13106097_OSXZ33YTWJ/www/online-kongresse.info/wp1/wp-content/plugins/autoptimize/classes/autoptimizeScripts.php(298): apply_filters('autoptimize_fil...', 'wp-includes/js/...', '<!DOCTYPE html>...') #3 /is/htdocs/wp13106097_OSXZ33YTWJ/www/online-kongresse.info/wp1/wp-content/plugins/autoptimize/classes/autoptimizeMain.php(591): autoptimizeScripts->read(Array) #4 [internal function]: autoptimizeMain->end_buffering('<!DOCTYPE html>...', 9) #5 /is/htdocs/wp13106097_OSXZ33YTWJ/www/online-kongresse.info/wp1/wp-includes/functions.php(5427): ob_end_flush() #6 /is/htdocs/wp13106097_OSXZ33YTWJ/www/online-kongresse.info/wp1/wp-includes/class-wp-hook.php(324): wp_ob_end_flush_all('') #7 /is/htdocs/wp13106097_OSXZ33YTWJ/www/online-kongresse.info/wp1/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array) #8 /is/htdocs/wp13106097_OSXZ33YTWJ/www/online-kongresse.info/wp1/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #9 /is/htdocs/wp13106097_OSXZ33YTWJ/www/online-kongresse.info/wp1/wp-includes/load.php(1280): do_action('shutdown') #10 [internal function]: shutdown_action_hook() #11 {main} thrown in /is/htdocs/wp13106097_OSXZ33YTWJ/www/online-kongresse.info/wp1/wp-content/plugins/pixelmate/include/pixelmate_includes.php on line 38