Few updates broke my CUSTOMIZER edits

Hello,

Frontend of my webpage is allright. But our client has backend access so he can edit his page and we’ve bouilt some editing possibilities into Theme -> Customize. In child theme I’ve got this chunk of code which worked:

function my_customizer_edits ( $wp_customize ) {  

	/* ABOUT US SECTION */
		$wp_customize->add_section( 'my_custom_about',
			array(
				'priority'       => 10,
				'capability'     => 'edit_theme_options',
				'theme_supports' => '',
				'title'          => __('O nás', 'mytheme'),
				'description'    =>  __('You can type your text here', 'mytheme'),
				'panel'  => 'tc-content-panel',
			)
		);
		$wp_customize->add_setting(
			'my_custom_about_us',
			array(
				'default' => 'Default text'
			)
		);
		$wp_customize->add_control(
			new Text_Editor_Custom_Control(
				$wp_customize,
				'my_custom_about_us',
				array(
					'label' => 'About',
					'section' => 'my_custom_about',
					'settings' => 'my_custom_about_us'
				)
			)
		);

	/* REMOVE STUFF */ 
		$wp_customize->remove_panel( 'widgets' );
		$wp_customize->remove_panel( 'nav_menus' );
		$wp_customize->remove_panel( 'tc-footer-panel' );
		$wp_customize->remove_panel( 'tc-advanced-panel');
		$wp_customize->remove_panel( 'tc-sidebars-panel');
		$wp_customize->remove_panel( 'tc-global-panel');
		$wp_customize->remove_panel( 'tc-header-panel');

		$wp_customize->remove_section('frontpage_sec');
		$wp_customize->remove_section('post_layout_sec');
		$wp_customize->remove_section('post_lists_sec');
		$wp_customize->remove_section('single_posts_sec');
		$wp_customize->remove_section('breadcrumb_sec');
		$wp_customize->remove_section('post_metas_sec');
		$wp_customize->remove_section('galleries_sec');
		$wp_customize->remove_section('paragraphs_sec');
		$wp_customize->remove_section('comments_sec');
		$wp_customize->remove_section('post_navigation_sec');

}
add_action( 'customize_register', 'my_customizer_edits ', 1000 );

I’m sure it has worked in 3.4.22 version of your theme. Now I checked (currently running 3.4.23) and it doesnt work and my client is unable to edit his page. When he goes to Theme -> Customize there are for a few seconds about ten items in left menu but when page fully loads, then there is only “Menu, Widgets, CSS” options.
What could’ve gone wrong?

Thank you