Fatal error: Uncaught Error: Call to undefined function imagecreatetruecolor() in /usr/local/www/apache24/data/wp-content/plugins/appointment-hour-booking/captcha/captcha.php:69 Stack trace: #0 /usr/local/www/apache24/data/wp-content/plugins/appointment-hour-booking/cp-main-class.inc.php(1252): include_once() #1 /usr/local/www/apache24/data/wp-includes/class-wp-hook.php(286): CP_AppBookingPlugin->data_management('') #2 /usr/local/www/apache24/data/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array) #3 /usr/local/www/apache24/data/wp-includes/plugin.php(453): WP_Hook->do_action(Array) #4 /usr/local/www/apache24/data/wp-settings.php(450): do_action('init') #5 /usr/local/www/apache24/data/wp-config.php(93): require_once('/usr/local/www/...') #6 /usr/local/www/apache24/data/wp-load.php(37): require_once('/usr/local/www/...') #7 /usr/local/www/apache24/data/wp-blog-header.php(13): require_once('/usr/local/www/...') #8 /usr/local/www/apache24/data/index.php(17): require('/usr/local/www/...') #9 {main} thro in /usr/local/www/apache24/data/wp-content/plugins/appointment-hour-booking/captcha/captcha.php on line 69