Hi @joaquimoliveira76, thanks for getting in touch.
Sometimes you will need to take a look at what’s going wrong in your PHP error logs as the critical error message usually appears because PHP errors are not set to display on a public-facing site. If you are unable to gain access to your site at all, look inside the /wp-content/plugins/ directory and rename the wordfence directory to wordfence.bak using your file manager or FTP access to your site.
You may need to reinstall the plugin from scratch, or change part of the configuration or file permissions depending on the requirements of your host. You can censor part of paths shown if you wish, but by all means paste the PHP errors you see to me here so that we can check if the site isn’t loading because of Wordfence, or a conflict/issue is arising elsewhere when you install the plugin.
Thanks,
Peter.