A seguir o conteúdo que deve estar presente no seu arquivo ".htaccess" caso utilize Links Permanentes:
# Início WordPress X2 Network
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# Fim WordPress X2 Network
