Appointments+ doesn't seem to be installing correctly

Hi there,

I have purchased and installed Appointments+, but when I come to activate I get the following errors:
Warning: Cannot modify header information - headers already sent by (output started at /home/dev1you/public_html/wp-content/plugins/appointment-plus-online-appointment-scheduling-widget/appointment-plus-scheduling.php:1) in /home/dev1you/public_html/wp-includes/option.php on line 568

Warning: Cannot modify header information - headers already sent by (output started at /home/dev1you/public_html/wp-content/plugins/appointment-plus-online-appointment-scheduling-widget/appointment-plus-scheduling.php:1) in /home/dev1you/public_html/wp-includes/option.php on line 569

Any ideas?