merhaba sayfam açılmıyordu 500 hatası veriyrdu facebook eklentisini devre dışı bıraktım yarım açılmaya başadı şu anda layerslider hata veriyor anladığım kadarıyla

error log dosyasına baktım

[01-Jan-2020 15:19:39 Europe/Istanbul] PHP Warning: Use of undefined constant DISABLE_WP_CRON - assumed 'DISABLE_WP_CRON' (this will throw an Error in a future version of PHP) in /home/kdldemir/public_html/wp-config.php on line 2
[01-Jan-2020 12:19:42 UTC] PHP Warning: Use of undefined constant wp_cumulus_widget - assumed 'wp_cumulus_widget' (this will throw an Error in a future version of PHP) in /home/kdldemir/public_html/wp-content/plugins/wp-cumulus/wp-cumulus.php on line 375
[01-Jan-2020 12:19:42 UTC] PHP Fatal error: Uncaught Error: [] operator not supported for strings in /home/kdldemir/public_html/wp-content/plugins/LayerSlider/includes/slider_markup_init.php:86
Stack trace:
#0 /home/kdldemir/public_html/wp-content/plugins/LayerSlider/wp/shortcodes.php(36): include()
#1 /home/kdldemir/public_html/wp-includes/shortcodes.php(325): layerslider_init(Array, '', 'layerslider')
#2 [internal function]: do_shortcode_tag(Array)
#3 /home/kdldemir/public_html/wp-includes/shortcodes.php(199): preg_replace_callback('/\[(\[?)(layers...', 'do_shortcode_ta...', '[layerslider id...')
#4 /home/kdldemir/public_html/wp-content/themes/nebula/page_f.php(36): do_shortcode('[layerslider id...')
#5 /home/kdldemir/public_html/wp-includes/template-loader.php(98): include('/home/kdldemir/...')
#6 /home/kdldemir/public_html/wp-blog-header.php(19): require_once('/home/kdldemir/...')
#7 /home/kdldemir/public_html/index.php(17): require('/home/kdldemir/...')
#8 {main}
thrown in /home/kdldemir/public_html/wp-content/plugins/LayerSlider/includes/slider_markup_init.php on line 86

bu hatayı alıyorum ne yapmam gerekiyor yardımcı olursanız sevinirim şimdiden tşkler...