WordPress There has been an error cropping your image

There has been an error cropping your image.

I ran into an issue when cropping my header image within WordPress. Turns out, WordPress uses the php-gd library to crop images.

wordpress_header_crop_error

Redhat / CentOS

yum install php-gd

Ubuntu

apt-get install php5-gd

Restart your web server (apache, httpd or nginx)

/etc/init.d/httpd restart