amitrh

I am also running into the same issue. i have added 'sanitize_callback' to every add_setting()
function but it still show the error. Please anyone Check My Code snippet and give me suggestion

function bookish_customize_register( $wp_customize ) {

	$wp_customize->get_setting( 'blogname' )->transport        = 'postMessage';
	$wp_customize->get_setting( 'blogdescription' )->transport = 'postMessage';

	$wp_customize->remove_control( 'header_textcolor' );
	$wp_customize->remove_control( 'background_color' );
	$wp_customize->remove_section( 'background_image' );
	$wp_customize->remove_section( 'header_image' );

	/*-----------------------------------------------------------*
	 * Assent Color  section
	 *-----------------------------------------------------------*/	

	$wp_customize->add_setting(
		'tcx_link_color',
		array(
			'default'     => '#000000',
			'sanitize_callback' => 'bookish_sanitize_text',
			'transport'   => 'postMessage',

		)
	);

	$wp_customize->add_control(
		new WP_Customize_Color_Control(
			$wp_customize,
			'link_color',
			array(
			    'label'      => __( 'Link Color', 'tcx' ),
			    'section'    => 'colors',
			    'settings'   => 'tcx_link_color'
			)
		)
	);
	/*-----------------------------------------------------------*
	 * Defining General Setting  section
	 *-----------------------------------------------------------*/

	$wp_customize->add_section(
		'bookish_general_setting',
		array(
			'title'     => 'General Settings',
			'priority'  => 1

		)
	);

   $wp_customize->add_setting(
			'bookish-logo',
			array(
				'default' => '',
				'sanitize_callback' => 'esc_url_raw',
				'transport'   => 'postMessage',

			)
		);

	$wp_customize->add_control(
		new WP_Customize_Image_Control(
			$wp_customize,
			'bookish-logo',
			array(
				'label'    => __( ' Logo', 'bookish' ),
				'section'  => 'bookish_general_setting',
				'settings' => 'bookish-logo',
				'priority' => 1

			)
		)
	);

	$wp_customize->add_setting(
			'bookish-retina-logo',
			array(
				'default' => '',
				'sanitize_callback' => 'esc_url_raw',
				'transport'   => 'postMessage',
			)
		);

	$wp_customize->add_control(
		new WP_Customize_Image_Control(
			$wp_customize,
			'bookish-retina-logo',
			array(
				'label'    => __( 'Retina Logo', 'bookish' ),
				'section'  => 'bookish_general_setting',
				'settings' => 'bookish-retina-logo',
				'priority' => 2

			)
		)
	);

	$wp_customize->add_setting(
		'bookish-favicon',
		array(
			'default'  => '',
			'sanitize_callback' => 'esc_url_raw',
			'transport'   => 'postMessage',

		)
	);

	$wp_customize->add_control(
		new WP_Customize_Image_Control(
			$wp_customize,
			'bookish-favicon',
			array(
				'label'    => __( ' Favicon', 'bookish' ),
				'section'  => 'bookish_general_setting',
				'settings' => 'bookish-favicon',
				'priority' => 3

			)
		)
	);

	$wp_customize->add_setting(
		'bookish-avatar',
		array(
			'default'          => '',
			'sanitize_callback' => 'esc_url_raw',
			'transport'   => 'postMessage',

		)
	);

	$wp_customize->add_control(
		new WP_Customize_Image_Control(
			$wp_customize,
			'bookish-avatar',
			array(
				'label'    => __( 'Avatar', 'bookish' ),
				'section'  => 'bookish_general_setting',
				'settings' => 'bookish-avatar',
				'priority' => 4
			)
		)
	);

	$wp_customize->add_setting(
		'bookish-retina-avatar',
		array(
			'default'          => '',
			'sanitize_callback' => 'esc_url_raw',
			'transport'   => 'postMessage',

		)
	);

	$wp_customize->add_control(
		new WP_Customize_Image_Control(
			$wp_customize,
			'bookish-retina-avatar',
			array(
				'label'    => __( 'Retina Avatar', 'bookish' ),
				'section'  => 'bookish_general_setting',
				'settings' => 'bookish-retina-avatar',
				'priority' => 5
			)
		)
	);

	$wp_customize->add_setting(
		'bookish_profile_name',
		array(
			'default'    =>  'Vincent Doe',
			'sanitize_callback' => 'bookish_sanitize_text',
			'transport'  =>  'postMessage',
		)
	);

	$wp_customize->add_control(
		'bookish_profile_name',
		array(
			'section'   => 'bookish_general_setting',
			'label'     => 'Profile Name',
			'type'      => 'text'
		)
	);

	$wp_customize->add_setting(
		'bookish_profile_desc',
		array(
			'default'    =>  'I lie close to the earth, a thousand unknown plants are noticed by me: when I hear the buzz of the little world among the stalks.',
			'sanitize_callback' => 'bookish_sanitize_textarea',
			'transport'  =>  'postMessage',

		)
	);

	$wp_customize->add_control(
		'bookish_profile_desc',
		array(
			'section'   => 'bookish_general_setting',
			'label'     => 'Profile Description',
			'type'      => 'textarea'
		)
	);

/*-----------------------------------------------------------*
 * Contact  section
 *-----------------------------------------------------------*/

	$wp_customize->add_section(
		'contact_setting',
		array(
			'title'     => 'Contact Info',
			'priority'  => 2
		)
	);

	$wp_customize->add_setting(
		'contact_heading',
		array(
			'default'    =>  'Get in touch',
			'sanitize_callback' => 'bookish_sanitize_text',
			'transport'  =>  'postMessage',
		)
	);

	$wp_customize->add_control(
		'contact_heading',
		array(
			'section'   => 'contact_setting',
			'label'     => 'Contact Heading',
			'type'      => 'text'
		)
	);

	$wp_customize->add_setting(
		'contact_email',
		array(
			'default'    =>  '',
			'sanitize_callback' => 'bookish_sanitize_email',
			'transport'  =>  'postMessage',
		)
	);

	$wp_customize->add_control(
		'contact_email',
		array(
			'section'   => 'contact_setting',
			'label'     => 'Email',
			'type'      =>  'email'

		)
	);

	$wp_customize->add_setting(
		'contact_phone',
		array(
			'default'    =>  '',
			'sanitize_callback' => 'bookish_sanitize_number',
			'transport'  =>  'postMessage',
		)
	);

	$wp_customize->add_control(
		'contact_phone',
		array(
			'section'   => 'contact_setting',
			'label'     => 'Phone Number',
			'type'      => 'text'
		)
	);

}

add_action( 'customize_register', 'bookish_customize_register', 11 );

/**
 * Binds JS handlers to make Theme Customizer preview reload changes asynchronously.
 */
function bookish_customize_preview_js() {
	wp_enqueue_script( 'bookish_customizer', get_template_directory_uri() . '/assets/js/customizer.js', array( 'customize-preview' ), '20130508', true );
}
add_action( 'customize_preview_init', 'bookish_customize_preview_js' );

function bookish_sanitize_text( $str ) {
	return sanitize_text_field( $str );
} 

function bookish_sanitize_textarea( $text ) {
	return esc_textarea( $text );
} 

function bookish_sanitize_number( $int ) {
	return absint( $int );
} 

function bookish_sanitize_email( $email ) {
	if(is_email( $email )){
		return $email;
	}else{
		return '';
	}
} 

function bookish_sanitize_file_url( $url ) {
	$output = '';
	$filetype = wp_check_filetype( $url );
	if ( $filetype["ext"] ) {
		$output = esc_url( $url );
	}
	return $output;
}

function tcx_customizer_css() {
?>
	 <style type="text/css">

		.TopBanner { background-color: <?php echo get_theme_mod( 'tcx_link_color' ); ?>!important; }

	 </style>
<?php
}
add_action( 'wp_head', 'tcx_customizer_css' );

Thanks in advance