How do I fix macOS Mojave httpd syntax error in a localhost setup?
It sounds like you do actually not have any configuration files in the /private/etc/apache2/users/ directory, and thus you cannot include them - therefore the configuration check fails.

If you have users on your system with shared a shared Sites folder, you would usually have configuration files in this directory named username.conf with the following contents:

&lt;Directory "/Users/username/Sites/"&gt;
    Options Indexes MultiViews
    Require all granted
&lt;/Directory&gt;


(Note: You'll need to replace "username" in the filename and the contents with the actual name of the user)