Fatal error

Hi Please help, everytime i try to click an image to my portfolio it gets me on this page and line of codes below:

Fatal error: Uncaught Error: Call to undefined method WP_Image_Editor_GD::get_error_message()
in /home/slomaymi/public_html/wp-content/themes/composer/framework/plugins/aq_resizer.php on line 146

Call stack:

Aq_Resize::process()
wp-content/themes/composer/framework/plugins/aq_resizer.php:240
aq_resize()
wp-content/themes/composer/framework/helpers/helpers.php:1018
composer_get_image()
wp-content/themes/composer/templates/single-portfolio/media/media-gallery.php:131
require()
wp-includes/template.php:725
load_template()
wp-includes/template.php:672
locate_template()
wp-includes/general-template.php:168
get_template_part()
wp-content/themes/composer/templates/single-portfolio/layout-two_column.php:41
require()
wp-includes/template.php:725
load_template()
wp-includes/template.php:672
locate_template()
wp-includes/general-template.php:168
get_template_part()
wp-content/themes/composer/single-pix_portfolio.php:22
include()
wp-includes/template-loader.php:106
require_once()
wp-blog-header.php:19
require()
index.php:17

The page I need help with: [log in to see the link]