Here is a simple solution if you are looking to have a password protected directory that is outside of WordPress. Just add two lines to the beginning of your .htaccess file and you're in business!
This article is great because it breaks down why it's not working.
#wordpress #troubleshooting #htaccess
How To: Fix WordPress 404 Errors on Password Protected Directories | My Guy Solutions – Web development, PHP, Web Design, E-Commerce, Denver, Colorado Springs
Using WordPress's permalink feature seems to cause some issues with password protected directories that use Apache's .htaccess to handle authentication. I recently had to troubleshoot why after install...