Debug and optimize website with elementor

We recently had our website and server optimized. However, as soon as we used elementor the website went buggy. I was turning on and off some themes/plugins and suddenly the website went buggy. I need someone to fix the bug and optimize my website, so that the server load (CPU) usage is not high. If you visit [login to view URL] there is an error: Warning: Declaration of tie_mega_menu_walker::start_el(&$output, $item, $depth, $args) should be compatible with Walker_Nav_Menu::start_el(&$output, $item, $depth = 0, $args = NULL, $id = 0) in /home/movieboo/public_html/wp-content/themes/sahifa_updated_theme/functions/[login to view URL] on line 0 Parse error: syntax error, unexpected end of file in /home/movieboo/public_html/wp-content/themes/sahifa_updated_theme/includes/widgets/[login to view URL] on line 45 There has been a critical error on your website. Learn more about debugging in WordPress.