Can't enter on wp-admin

Try manually resetting your plugins (no Dashboard access required). If that resolves the issue, reactivate each one individually until you find the cause.

If that does not resolve the issue, access your server via SFTP or FTP, or a file manager in your hosting account’s control panel, navigate to /wp-content/themes/ and rename the directory of your currently active theme. This will force the default theme to activate and hopefully rule-out a theme-specific issue (theme functions can interfere like plugins).

You’re getting a white screen, that’s generally caused by a fatal PHP error. I’ll bet there is a plugin conflict with the latest version of WordPress.

You can either check your server’s error logs or systematically deleting (renaming works too) your plugins until you regain access. Try removing one plugin at a time and testing the login screen.

I deactivate all plugins with no results, and when I rename the theme all the site shows a blank page…

Renaming the theme will just confuse WordPress as it will keep looking for the old theme folder and thus will give you a white screen.

If you’ve deactivated all the plugins and you still can’t login check out the apache error logs. There might be some fatal errors preventing you from being able to login. You could also try re-uploading a fresh copy of of your theme.

No problems with the plugins and theme, now I can enter on https://fullbeta.com/wp-login.php but I see a problem with cookies…

Also, I recently found that the header is moved down on https://www.fullbeta.com