I'm using Contact Form 7 on a multi-site.
When using the Really Simple Captcha plugin, the contact form fails and throws up the error message:
Fatal error: Call to undefined function imagetypes() in /home/xxxmysitexxx/public_html/wp-content/plugins/contact-form-7/modules/captcha.php on line 360
The problem seems to be with the challenge shortcode:
[captchac captcha-1 fg:#FFFFFF bg:#FFFFFF]
The second shortcode doesn't return any error and displays the input box ok.
I hope you can help me resolve this issue asap. Thank you.