Fatal error: Uncaught Error: Call to undefined function imagecreatetruecolor() in /var/www/html/captcha.php:244 Stack trace: #0 /var/www/html/captcha.php(197): SimpleCaptcha->ImageAllocate() #1 /var/www/html/captcha.php(43): SimpleCaptcha->CreateImage() #2 {main} thrown in /var/www/html/captcha.php on line 244