Hi, is it WP multi-site? 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$ [-])
If it’s still the issue then please let us know your website’s wp-admin login details and FTP details (as private reply), so that we can look into it further.