Have installed to my server and all went ok but when I go to the Payments menu in Admin at the top of the page I get this error message

Warning: main(/usr/local/psa/home/vhosts/aumz.com/httpdocs/zen/includes/modules/payment/paypal/paypal_curl.php): failed to open stream: Permission denied in /usr/local/psa/home/vhosts/aumz.com/httpdocs/zen/includes/modules/payment/paypalwpp.php on line 15

Fatal error: main(): Failed opening required '/usr/local/psa/home/vhosts/aumz.com/httpdocs/zen/includes/modules/payment/paypal/paypal_curl.php' (include_path='.:/usr/local/psa/apache/lib/php') in /usr/local/psa/home/vhosts/aumz.com/httpdocs/zen/includes/modules/payment/paypalwpp.php on line 15