"Permission denied""PHP Fatal error: Unknown: Failed opening required '/var/www/osticket/upload/setup/index.php'"One of the following: SELinux or mod_security is running and preventing the access (or after you changed them you didn't restart Apache).Your HTTP config is preventing the file from being accessed. Check your .htaccess files, and http.conf (and include files).your files are not accessible by the username that your Apache is running as. Check your owner/group settings.
This might point you in the right direction also:
http://unix.stackexchange.com/questions/181177/apache-httpd-cannot-parse-php-on-centos-7