Can’t access Menu

Hi,

It’s not possible to access the MENU page from APPEARANCE. I am getting these error messages:

An error of type E_ERROR was caused in line 111 of the file [WEBSITE-SERVER-PATH-REMOVED]/wp-content/plugins/themebeez-toolkit/includes/simple-mega-menu/class-simple-mega-menu-fields.php. Error message: Uncaught Error: Using $this when not in object context in [WEBSITE-SERVER-PATH-REMOVED]/wp-content/plugins/themebeez-toolkit/includes/simple-mega-menu/class-simple-mega-menu-fields.php:111
Stack trace:
#0 [WEBSITE-SERVER-PATH-REMOVED]/wp-includes/class-wp-hook.php(289): Simple_Mega_Menu_Fields::create_menu_fields(814, Object(WP_Post), 0, Object(stdClass))
#1 [WEBSITE-SERVER-PATH-REMOVED]/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters('', Array)
#2 [WEBSITE-SERVER-PATH-REMOVED]/wp-includes/plugin.php(478): WP_Hook->do_action(Array)
#3 [WEBSITE-SERVER-PATH-REMOVED]/wp-content/plugins/themebeez-toolkit/includes/simple-mega-menu/class-simple-mega-menu-nav-walker-edit.php(94): do_action('wp_nav_menu_ite...', 814, Object(WP_Post), 0, Object(stdClass), 0)
#4 [WEBSITE-SERVER-PATH-REMOVED]/wp-content/plugins/themebeez-toolkit/includes/simple-mega-menu/class-simple-mega-menu-nav-walker-edit.php(56): Simple_Mega_Menu_Nav_Walker_Edit->get_fields(Object(WP_Post), 0, Object(stdClass))
#5 [WEBSITE-SERVER-PATH-REMOVED]/wp-includes/class-wp-walker.php(144): Simple_Mega_Menu_Nav_Walker_Edit->start_el('', Object(WP_Post), 0, Object(stdClass))
#6 [WEBSITE-SERVER-PATH-REMOVED]/wp-includes/class-wp-walker.php(244): Walker->display_element(Object(WP_Post), Array, 0, 0, Array, '')
#7 [WEBSITE-SERVER-PATH-REMOVED]/wp-includes/nav-menu-template.php(584): Walker->walk(Array, 0, Object(stdClass))
#8 [WEBSITE-SERVER-PATH-REMOVED]/wp-admin/includes/nav-menu.php(1077): walk_nav_menu_tree(Array, 0, Object(stdClass))
#9 [WEBSITE-SERVER-PATH-REMOVED]/wp-admin/nav-menus.php(512): wp_get_nav_menu_to_edit(168)
#10 {main}
  thrown

Can you please help ASAP?

Thanks