Plugin Error

Hello,
whenever I am uploading a new plugin I receive this error message:

Notice: Undefined index: facebook-page-promoter-lightbox-premium/index.php in /www/htdocs//wp-content/plugins/facebook-page-promoter-lightbox-premium/class-updater-premium.php on line 29

Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w0179464/wp-content/plugins/facebook-page-promoter-lightbox-premium/class-updater-premium.php:29) in /www/htdocs//wp-includes/pluggable.php on line 1219

Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w0179464/wp-content/plugins/facebook-page-promoter-lightbox-premium/class-updater-premium.php:29) in /www/htdocs//wp-includes/pluggable.php on line 1219

Can anyone help?