
This question has been answered by fourroses666. See the first response.

# Friendly URLs
RewriteEngine On
RewriteBase /
# Fix Apache internal dummy connections from breaking [(site_url)] cache
RewriteCond %{HTTP_USER_AGENT} ^.*internal\ dummy\ connection.*$ [NC]
RewriteRule .* - [F,L]
# Exclude /assets and /manager directories from rewrite rules
RewriteRule ^(manager|assets) - [L]
# Redirect from mydomain.com/rootname to mydomain.com/rootname/
RewriteRule ^nl$ nl/ [R=301,L]
RewriteRule ^en$ en/ [R=301,L]
# The Friendly URLs part
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^nl/(.*)$ index.php?q=$1 [L,QSA]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^en/(.*)$ index.php?q=$1 [L,QSA]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?q=$1 [L,QSA]
Did you made a mistake while changing or updating YAMS maybe?
Did you placed the config file from your old version in the new?

RewriteEngine On
RewriteBase /sites/marquisats2
# Fix Apache internal dummy connections from breaking [(site_url)] cache
RewriteCond %{HTTP_USER_AGENT} ^.*internal\ dummy\ connection.*$ [NC]
RewriteRule .* - [F,L]
# Exclude /assets and /manager directories and images from rewrite rules
RewriteRule ^(manager|assets)/.*$ - [L]
RewriteRule \.(jpg|jpeg|png|gif|ico)$ - [L]
# Redirect from mydomain.com/rootname to mydomain.com/rootname/
RewriteRule ^en$ en/ [R=301,L]
# The Friendly URLs part
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^en/(.*)$ index.php?q=$1 [L,QSA]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?q=$1 [L,QSA]
