I can't install component

I get the following error when I try to install component:
Thanks


* JInstaller: :Install: SQL File not found /Users/marta/Sites/www/administrator/components/com_communityquiz/sql/install.mysql.utf8.sql
* Component Install: SQL error file DB function reports no errors
* Failed loading XML file
* /Users/marta/Sites/www/plugins/plg_jquery/jquery/jquery.xml
* XML: failed to load external entity "/Users/marta/Sites/www/plugins/plg_jquery/jquery/jquery.xml"
* Failed loading XML file
* /Users/marta/Sites/www/plugins/plg_jquery/jquery/jquery.xml
* XML: failed to load external entity "/Users/marta/Sites/www/plugins/plg_jquery/jquery/jquery.xml"
* XML: failed to load external entity "/Users/marta/Sites/www/plugins/plg_jquery/jquery/jquery.xml"