Visforms captcha does not show an image
Note: This article is related to the captcha that is displayed when you select the "Visforms Captcha" setting in the form.
The so-called Visforms Captcha uses the free, open-source PHP CAPTCHA Script. The characters displayed on the captcha image are generated using PHP code.
Therefore, the script makes some demands on the PHP system requirements and PHP settings on the server. Unfortunately, these requirements are not met in a few cases. One requirement is that the PHP “FreeType” extension is present and enabled in the PHP settings.
If the extension is missing or deactivated, the captcha image cannot be generated and therefore cannot be displayed. In the background, the error message “Call to undefined function imagettftext()” is output in securimage.php.
To check whether the “FreeType” extension is installed and activated, go to the menu item System » System information in the administration of your Joomla installation. Click on the “PHP Information” tab. Use your web browser’s search function and search for “FreeType”. This PHP extension must be installed and activated.
Note: You can usually open the search function of your browser by pressing the key combination "Ctrl" + "f".
If the extension is not installed or not activated, you must clarify with your provider whether it is possible to activate the extension. If activation is not possible, unfortunately you cannot use the Visforms captcha. Try Google Recaptcha instead, or use the extremely effective “Visforms Spam Protection Plugin”. More on this in: Spam protection for forms.
The PHP CAPTCHA script authors’ website has a FAQ. The known problems, their causes and possible solutions are described there.