Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/bee10c764f03908f8ee0a87f1b8be7c7.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563