Webform : A partially-completed form was found. Please complete the remaining portions Yesterday I have updated webform module from 7.x-4.0-beta3 to 7.x-4.9.

Post to that I am getting this notification message, throughout the site :


  A partially-completed form was found. Please complete the remaining portions


I have also checked some threads : 

https://www.drupal.org/node/2483859

https://www.drupal.org/node/2278177

When I check log entries I got this  error :


  Notice: Undefined property: stdClass::$is_draft in webform_client_form()


Which suggest that some alteration leading this issue but unable to get any solution.
Try this:
Delete the form submission that is having problem(that is the submission id that is partially filled) in the following tables:

webform_submitted_data
webform_submission