Column 'pid' cannot be null

Problem/Motivation

PDOException: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'pid' cannot be null: INSERT INTO {webform_component} (nid, cid, pid, form_key, name, type, value, extra, required, weight) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7, :db_insert_placeholder_8, :db_insert_placeholder_9); Array ( [:db_insert_placeholder_0] => 809 [:db_insert_placeholder_1] => 62 [:db_insert_placeholder_2] => [:db_insert_placeholder_3] => order_status [:db_insert_placeholder_4] => Order Status [:db_insert_placeholder_5] => hidden [:db_insert_placeholder_6] => Did not complete checkout [:db_insert_placeholder_7] => a:2:{s:20:"conditional_operator";s:1:"=";s:7:"private";i:0;} [:db_insert_placeholder_8] => 0 [:db_insert_placeholder_9] => -100 ) in webform_component_insert() (line 814 of /chroot/home/oceanbea/oceanbeachsandiego.com/html/sites/all/modules/webform/includes/webform.components.inc).

Steps to reproduce

Create at least two Ubercart products (SKUs 'product001 A' and 'product002 B'). Configure a webform with a product.

Add the product component to the webform and enter the first product in the autocomplete input field. Save the webform.

Now, go back to the webform and change the reference to the product by changing just the NID_SKU instead of entering a new title.

Example: change SKU '1_product001 A' to '2_product002 B'.