HTTP Error

I get this with the latest version:

[13-Jan-2018 12:37:11 UTC] PHP Warning:  Illegal string offset 'sizes' in /var/www/html/yyy/wp-content/plugins/image-regenerate-select-crop/image-regenerate-select-crop.php on line 1163
[13-Jan-2018 12:37:11 UTC] PHP Fatal error:  Uncaught Error: Cannot use string offset as an array in /var/www/html/yyy/wp-content/plugins/image-regenerate-select-crop/image-regenerate-select-crop.php:1163
Stack trace:
#0 /var/www/html/yyy/wp-content/plugins/image-regenerate-select-crop/image-regenerate-select-crop.php(262): SIRSC_Image_Regenerate_Select_Crop::make_images_if_not_exists(5228, 'thumbnail', 'ct')
#1 /var/www/html/yyy/wp-includes/class-wp-hook.php(286): SIRSC_Image_Regenerate_Select_Crop::process_filtered_attachments(28368, 5228, '_wp_attachment_...', Array)
#2 /var/www/html/yyy/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters('', Array)
#3 /var/www/html/yyy/wp-includes/plugin.php(453): WP_Hook->do_action(Array)
#4 /var/www/html/yyy/wp-includes/meta.php(122): do_action('added_post_meta', 28368, 5228, '_wp_attachment_...', Array)
#5 /var/www/html/yyy/wp-includes/meta.php(202): add_metadata('post', 5228, '_wp_attachment_...', 'a:1:{s:5:"sizes...')
#6 /var/www/html/ in /var/www/html/yyy/wp-content/plugins/image-regenerate-select-crop/image-regenerate-select-crop.php on line 1163