Fatal error: Uncaught exception 'Exception' with message 'Illegal widget setting ID

Question

i recently noticed that when try to load Appearance > Customize i get this error:

Notice: Trying to get property of non-object in /home/kavwxoln/feelfreehypnosis.com/wp-includes/class-wp-customize-nav-menus.php on line 682

Fatal error: Uncaught exception 'Exception' with message 'Illegal widget 
setting ID: nav_menu_item[]' in /home/kavwxoln/feelfreehypnosis.com/wp- 
includes/customize/class-wp-customize-nav-menu-item-setting.php:171 Stack trace: #0 /home/kavwxoln/feelfreehypnosis.com/wp-includes/class-wp-customize-nav-menus.php(693): WP_Customize_Nav_Menu_Item_Setting->__construct(Object(WP_Customize_Manager), 'nav_menu_item[]', Array) #1 [internal function]: WP_Customize_Nav_Menus->customize_register(Object(WP_Customize_Manager)) #2 /home/kavwxoln/feelfreehypnosis.com/wp-includes/class-wp-hook.php(286): call_user_func_array(Array, Array) #3 /home/kavwxoln/feelfreehypnosis.com/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters('', Array) #4 /home/kavwxoln/feelfreehypnosis.com/wp-includes/plugin.php(453): WP_Hook->do_action(Array) #5 /home/kavwxoln/feelfreehypnosis.com/wp-includes/class-wp-customize-manager.php(926): do_action('customize_regis...', Object(WP_Customize_Manager)) #6 [internal function]: WP_Customize_Manager->wp_loaded('' in /home/kavwxoln/feelfreehypnosis.com/wp-includes/customize/class-wp-customize-nav-menu-item-setting.php on line 171

I searched on Google and found this thread but when apply the answer provided there :

ALTER TABLE `wp_terms`
CHANGE COLUMN `term_id` `term_id` BIGINT(20) UNSIGNED NOT NULL 
AUTO_INCREMENT FIRST,
ADD PRIMARY KEY (`term_id`),
ADD INDEX `name` (`name`),
ADD INDEX `slug` (`slug`);

i get this answer from phpmyadmin:

#1068 - Multiple primary key defined

So im seaching for asnwer how to fix this issue.

Answer 1

This is what i do:

1. Go to database via Phpmyadmin, then make backup from wp_terms table ONLY !

2. Go to SQL editor and paste this code:

   CREATE TABLE wp_terms ( term_id bigint(20) unsigned NOT NULL AUTO_INCREMENT, name varchar(200) NOT NULL DEFAULT '', slug varchar(200) NOT NULL DEFAULT '', term_group bigint(10) NOT NULL DEFAULT '0', PRIMARY KEY (term_id), UNIQUE KEY slug (slug), KEY name (name) ) ENGINE=MyISAM AUTO_INCREMENT=603 DEFAULT CHARSET=utf8;

3. Open previous saved backup from .sql file, and insert it via SQL editor using phpmyadmin.

Problem solved !

NOTE: Get only lines from backup, not entire database !