I'm getting a 500 error when I turn on progress bar. I followed all the directions and can't get it to work. My config is above:

$base_dir = '/var/www/vhosts/mysite.com/httpdocs';

$config = {
config_file_name => 'uu_default_config',
temp_dir => $base_dir . '/var/www/vhosts/mysite.com/httpdocs/templates_c/',
upload_dir => $base_dir . '/var/www/vhosts/mysite.com/httpdocs/video/',
unique_upload_dir => 0,
unique_upload_dir_length => 16,
unique_file_name => 0,
unique_file_name_length => 16,
max_upload => 20971520000,
overwrite_existing_files => 0,
redirect_after_upload => 1,
param_dir => $base_dir . '/var/www/vhosts/mysite.com/httpdocs/templates_c/',
pass_param_dir => 1,
redirect_url => 'http://www.mysite.com/upload.php',
redirect_using_js_html => 1,
redirect_using_html => 0,
redirect_using_js => 0,
redirect_using_location => 0,
get_data_speed => 1000,
disallow_extensions => '(sh|php|php3|php4|php5|py|shtml|phtml|cgi|pl|plx| mp3|exe|scr|htaccess|htpasswd)',
allow_extensions => '(3gp|mp4|mov|asf|avi|flv|wmv|mpg|mpeg|mpeg4|xvid| divx|3gpp)',
normalize_file_names => 1,
normalize_file_delimiter => '_',
normalize_file_length => 32,
link_to_upload => 0,
path_to_upload => 'http://'. $ENV{'SERVER_NAME'} . '/uploads/',
send_email_on_upload => 0,
html_email_support => 0,
link_to_upload_in_email => 0,
email_subject => 'MySite Video Upload',
to_email_address => '[email protected],[email protected]',
from_email_address => '[email protected]',
log_uploads => 0,
log_params => 0,
log_dir => $base_dir . '/var/www/vhosts/mysite.com/httpdocs/templates_c/',