1. Enable multisite
2. Deactivate all installed plugins
3. Create network
4. Update config files

Keep in mind that creating sites in subdirectories doesn’t actually create any subdirectories on the file system, so you won’t see any new folders. It is all done within the database except maybe a folder under wp-content/uploads for Media files..

Enable multisite

Add the following to wp-config.php (before any require or include statements..)

/**
 * Allow WordPress Multisite network
 */
define( 'WP_ALLOW_MULTISITE', true );

Once you have it enabled, go back to Dashboard > Tools > Network Setup and confirm the settings. You’ll then be asked to edit the wp-config.php and .htaccess files again

Update configuration files

// wp-config.php
/**
 * Allow WordPress Multisite network
 */
define( 'WP_ALLOW_MULTISITE', true );
define('MULTISITE', true);
define('SUBDOMAIN_INSTALL', false); // Set this to true for subdomain sites
define('DOMAIN_CURRENT_SITE', 'mydomain.net');
define('PATH_CURRENT_SITE', '/');
define('SITE_ID_CURRENT_SITE', 1);
define('BLOG_ID_CURRENT_SITE', 1);

Replace the existing WordPress related rules with the following

# .htaccess

# BEGIN WordPress
# The directives (lines) between `BEGIN WordPress` and `END WordPress` are
# dynamically generated, and should only be modified via WordPress filters.
# Any changes to the directives between these markers will be overwritten.
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]
RewriteRule . index.php [L]
</IfModule>
# END WordPress

Subdomain or Paths (Subdirectories)

You can set the SUBDOMAIN_INSTALL option to true or false and that’ll change the option you get when creating a new site. By default, it starts with installs in subdomains. I had to go in and change the value to false in order to create new sites in subdirectories

define('SUBDOMAIN_INSTALL', false);

Create sites

The above is all you need. You should now be able to go to https://mydomain.net/wp-admin/network/ and create new sites, update all plugins and update all themes etc.

Management

• You should configure plugins like JetPack from the Network Admin
• I can install plugins from the Network Admin or from the Main site

Troubleshooting

You get too many redirects when going to the Admin of the new site you just created

ERR_TOO_MANY_REDIRECTS

Check your .htaccess file. In my case i had added the code for subdomains and had later switched to subfolders. The .htaccess snippet for both is different.

Subfolder Example

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]
RewriteRule . index.php [L]

SubDomain Example

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

# add a trailing slash to /wp-admin
RewriteRule ^wp-admin$ wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^(wp-(content|admin|includes).*) $1 [L]
RewriteRule ^(.*\.php)$ $1 [L]
RewriteRule . index.php [L]

Links

• Before You Create A Network
• Create A Network
• htaccess: Multisite

https://wetopi.com/how-to-setup-wordpress-multisite-with-subdirectories/