When my Drupal CiviCRM Webform is filled out and submitted, the CiviCRM database appears to be updated correctly. That is, a new contact is created with all the proper information included from the form. The Webform confirmation page announces: "Thank you, your submission has been received." However, a red error box also appears that says:
"Warning: implode(): Invalid arguments passed in CRM_Core_BAO_CustomGroup::postProcess() (line 1551 of /home/mywebsite/www/crm/sites/all/modules/civicrm/CRM/Core/BAO/CustomGroup.php)."
Any idea what this means and how to get rid of the error message?
Drupal 7, CiviCRM 5.14.1