ferencvirag

I did these steps:

1. You must take a backup of full multisite, all files and including the database.
2. Open wp-config.php file and change
define(‘SUBDOMAIN_INSTALL’, false);

to
define(‘SUBDOMAIN_INSTALL’, true);

3. Change your htaccess to
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).*) $1 [L]
RewriteRule ^(.*\.php)$ wp/$1 [L]
RewriteRule . index.php [L]