Hi, depending on your websever and WP installation, you have to follow one of these:

1) If it’s Apache webserver and WP single site installation, then follow these steps (your site’s htaccess file should be writeable):

– goto HMWP >> ‘Start’ Tab >> ‘Medium Privacy – More Compatibility’ scheme >> click ‘Save Settings’

2) If it’s Apache server and WP multisite, follow these steps:

– goto HMWP >> ‘Start’ Tab >> select ‘Medium Privacy – More Compatibility’ scheme >> click ‘Save Settings’
– goto HMWP >> ‘Start’ Tab >> click ‘Multi-site Configuration’
– now use a FTP program or your host file manager and add those lines to your htaccess file (after RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ [-])

3) If it’s Nginx server and WP single site, follow these steps:

– goto HMWP >> ‘Start’ Tab >> ‘Medium Pripacy – More Compatibility’ scheme >> click ‘Save Settings’

– In Start tab you should see Nginx Configuration button. If you don’t see this button, add &nginx_config=1 to HMWP settings page URL to see Nginx rewrite rules. For example:
http://yourdomain.com/wp-admin/options-general.php?page=hide_my_wp&nginx_config=1

– Now add those lines (rewrite rules) to your Nginx configuration file. It’s usually located in /etc/nginx/nginx.conf or /etc/nginx/conf/nginx.conf or /etc/nginx/sites-available/domainname.com

– restart nginx server

Let us know if you are still having issue.