Warning: array_shift() expects parameter 1 to be array error in WP post loop

I get

Warning: array_shift() expects parameter 1 to be array, boolean given in C:\wamp\www\Dropbox\ktechwp\wp-content\themes\ktech\single-shredders.php on line 118

for a loop that goes to the taxonomy ‘shredder-usage’ under custom post type ‘shredders’ and shows all the post under that taxonomy term. The following code works in the single-safes.php

<div id="othrsizes"><h2>Other Products</h2>

<?php

$sectors = get_the_terms( get_the_ID(), 'safe-type' );

if ( ! is_wp_error( $sectors ) ) {

	$term = array_shift( $sectors );

	/* Query for jobs that are in the sector. */

	$jobs = null;

	if ( isset( $term->slug ) && isset( $term->taxonomy ) ) {

		$jobs = get_posts( array(

			'term'        => $term->slug,

			'taxonomy'    => $term->taxonomy,

			'post_type'   => 'safes',

			'post_status' => 'publish',

			) );

	}

	/* Loop over all jobs and display an unordered list. */

	if ( $jobs ) {

		$_post = $post;

		print '<ul>';

		foreach ( (array) $jobs as $post ) {

			setup_postdata( $post );
			echo '<div class="productimg"><a href="' . esc_url( get_permalink() ) . '">';
			the_post_thumbnail();
			the_title( '<li><a href="' . esc_url( get_permalink() ) . '">', '</a></li>' );

			if(get_field('new_price'))
			{
				echo '<span class="old_price">Rs. ' .get_field('price') . '</span> > <span class="price">Rs. ' . get_field('new_price') . '</span>';
			}
			else
			{
				echo '<span class="price">Rs. ' . get_field('price') . '</span>';
			}

			echo "</a></div>";

		}

		print '</ul>';

		$post = $_post;

	}

}

?>

    </div>

but the following code which is the same after I change the taxanomy name ‘safes’ top ‘shredder-usage’ and post type ‘safes’ to ‘shredders’ does not work and gives me warning mentioned above.

<div id="othrsizes"><h2>Other Products</h2>

<?php

$sectors = get_the_terms( get_the_ID(), 'shredder-usage' );

if ( ! is_wp_error( $sectors ) ) {

	$term = array_shift( $sectors );

	/* Query for jobs that are in the sector. */

	$jobs = null;

	if ( isset( $term->slug ) && isset( $term->taxonomy ) ) {

		$jobs = get_posts( array(

			'term'        => $term->slug,

			'taxonomy'    => $term->taxonomy,

			'post_type'   => 'shredders',

			'post_status' => 'publish',

			) );

	}

	/* Loop over all jobs and display an unordered list. */

	if ( $jobs ) {

		$_post = $post;

		print '<ul>';

		foreach ( (array) $jobs as $post ) {

			setup_postdata( $post );
			echo '<div class="productimg"><a href="' . esc_url( get_permalink() ) . '">';
			the_post_thumbnail();
			the_title( '<li><a href="' . esc_url( get_permalink() ) . '">', '</a></li>' );

			echo "</a></div>";

		}

		print '</ul>';

		$post = $_post;

	}

}

?>

    </div>

Please review and help