I am getting this error when I run on my mac with localhost.
Either GD PHP extension with FreeType support or ImageMagick PHP extension with PNG support
For solve problem, first install php-gd module on your system. After that open php.ini on your editor and search for ;extension=gd.so and remove the heading ; sign. Then restart your apache service ;).
For Arch Linux you can do followings (Lines that begins with # are command of terminal):
# pacman -S php-gd# vim /etc/php/php.ini/ and type gd then press Enter;extension=gd.so and convert it into extension=gd.so by moving cursor on ; sign and press xEsc and type :wq and press Enter# systemctl restart httpd.serviceInfact in Windows 10 environment, installed with WAMP Server, it was a matter of copying php.ini file to C:\wamp64\bin\apache\apache2.4.27\bin\
It was missing at that location.
On windows, if you already install php > 7.0, then Check php_gd2.dll is in your extension directory and uncomment ;extension=gd2 of your php.ini.
With this two lines it is okeyokay:
sudo apt install php-gd
sudo service apache2 restart
As suggested in the comments.
The contact form contains a .png picture in the form of a captcha image. The captcha image is used there to prevent spam being send via the contact form.
Try un-commenting extension=gd2 in php.ini. Then restart apache.