Hi,
Sorry to hear that. You can check the server’s error log to see what the error actually is and let me know but the only thing I can think of is that your server does not have the PHP GD extension installed/enabled (https://www.php.net/manual/en/intro.image.php) It provides the standard image processing functions for PHP and if it’s missing, it cannot generate the captcha image 🙁
Thanks I will check tonight with my provider.
If my provider do not have this feature, how can I disable the captcha ? Actualiy I can not acces my admin dashboard in wordpress.
Unfortunately, at this point you would have to disable the plugin via FTP (renaming the login-lockdown plugin folder or deleting it), then login to wp-admin and if you want enable login-lockdown again and while still logged in, disable the captcha in the plugin settings.
The other Captcha options in Login Lockdown PRO (reCAPTCHA, hCaptcha) don’t use images generated locally so those should work 🙂