Wordpress - multisite 404 error for subdirectory

I had the axact same problem.

My solution: edited/etc/apache2/sites-enabled/000-default.conf. It needs to look like:

<VirtualHost *:80>

        ServerAdmin webmaster@localhost
        DocumentRoot /var/www/html

        <Directory />
                Options FollowSymLinks
                AllowOverride all
        </Directory>
        <Directory /var/www/>
                Options FollowSymLinks
                AllowOverride all
                Order allow,deny
                allow from all
        </Directory>

        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined

</VirtualHost>

It works!

I faced same problem - wordpress multisite directory - 404 error for new site dashboard and site page, admin site and dashboard works.

My problem was in apache configuration - /etc/apache2/httpd.conf. Need to do 'AllowOverride All' under Section <Directory "/Users/user1/Sites">

And don't forget to enable mod_rewrite in httpd.conf:

LoadModule rewrite_module libexec/apache2/mod_rewrite.so

Otherwise it gives 500 error.

I don't know what these config represent, but this solved my problem. Hope this helps.