modifica il file lasciando solo questo contenuto ( ed attivando solo l'opzione che serve - leggi bene il testo):

RewriteEngine on

If Elgg is in a subdirectory on your site, you might need to add a RewriteBase line

containing the path from your site root to elgg's root. e.g. If your site is

http: //example.com/ and Elgg is in http: //example.com/sites/elgg/, you might need

#RewriteBase /sites/elgg/

here, only without the # in front.

If you're not running Elgg in a subdirectory on your site, but still getting lots

of 404 errors beyond the front page, you could instead try:

RewriteRule ^action/([A-Za-z0-9_-/]+)$ engine/handlers/action_handler.php?action=$1&%{QUERY_STRING}

RewriteRule ^services/api/([A-Za-z0-9_-]+)/(.*)$ engine/handlers/service_handler.php?handler=$1&request=$2&%{QUERY_STRING}

RewriteRule ^export/([A-Za-z]+)/([0-9]+)$ services/export/handler.php?view=$1&guid=$2
RewriteRule ^export/([A-Za-z]+)/([0-9]+)/$ services/export/handler.php?view=$1&guid=$2
RewriteRule ^export/([A-Za-z]+)/([0-9]+)/([A-Za-z]+)/([A-Za-z0-9_]+)/$ services/export/handler.php?view=$1&guid=$2&type=$3&idname=$4

RewriteRule ^_css/css.css$ _css/css.php

RewriteRule ^pg/([A-Za-z0-9_-]+)/(.*)$ engine/handlers/pagehandler.php?handler=$1&page=$2&%{QUERY_STRING}
RewriteRule ^pg/([A-Za-z0-9_-]+)$ engine/handlers/pagehandler.php?handler=$1&%{QUERY_STRING}

RewriteRule xml-rpc.php engine/handlers/xml-rpc_handler.php
RewriteRule mt/mt-xmlrpc.cgi engine/handlers/xml-rpc_handler.php

RewriteRule ^tag/(.+)/?$ engine/handlers/pagehandler.php?handler=search&page=$1