WP 4.9.5
Piklist 0.9.9.15

I had a file upload field associated with a custom post type that was working correctly in 0.9.9.12:

piklist('field', array(
    'type' => 'file',
	'field' => '_job_download',
	'scope' => 'post_meta',
	'label' => 'Downloadable Job Description',
	'options' => array(
		'basic' => true
	)
));

What I tried:

1. Add new post
2. Click file upload “Browse…” button, choose a file
3. Save a draft of the post

What I expected:

I expected to see something representing the file I attached below the “Browse…” button, with the file name and a button to remove it.

What I got:

No indication that the file attachment was successful. With WP_DEBUG on, I get the following warnings after saving a draft, and they appear on a blank white page (no WP admin UI loads in this case):

Warning: Invalid argument supplied for foreach() in /var/www/html/wp-content/plugins/piklist/includes/class-piklist.php on line 1533

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/piklist/includes/class-piklist.php:1533) in /var/www/html/wp-admin/includes/misc.php on line 1116

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/piklist/includes/class-piklist.php:1533) in /var/www/html/wp-admin/post.php on line 198

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/piklist/includes/class-piklist.php:1533) in /var/www/html/wp-includes/pluggable.php on line 1216

Thanks!