Captcha doesn't work for my site I'm using Drupal for my site, and I activated the CAPTCHA image for the login of the administration user. However, it doesn't work.

I don't see the CAPTCHA image, which is replaced by a placeholder.


  


Why does this happen? Do I need to fix something in the settings?

May you tell me how I can, at least, skip this verification to be able to log in, and remove the CAPTCHA for my account?
The issue was because the PHP GD Library was not installed in my machine...  So I installed the GD Library using sudo yum install php56w-gd and the things working good actually.

Note that to access to admin page (my aim) we can deactivate the captcha module using  this command : drush dis captcha