Pluin Error

Can anyone help to identify what this error code is and why we are getting it on our site?

Notice: Undefined index: post_type in /hermes/bosoraweb095/b1794/ipg.woodypeck/wp-content/plugins/wc-product-bundles/wcpb.php on line 40 Warning: Cannot modify header information – headers already sent by (output started at /hermes/bosoraweb095/b1794/ipg.woodypeck/wp-content/plugins/wc-product-bundles/wcpb.php:40) in /hermes/bosoraweb095/b1794/ipg.woodypeck/wp-includes/pluggable.php on line 1228