When editing and then saving a relationship, the AJAX overlay hangs with the spinning symbol. If the page is refreshed, the 'Relationship record has been updated." notification is shown and the change is saved in the DB
POST http://www.example.com/civicrm/contact/view/rel?action=update&cid=1234&id=4321&rtype=a_b&snippet=json 500 (Service unavailable (with message))
In syslog I'm getting the error:
http://www.example.com/civicrm/contact/view/rel?action=update&cid=24068&id=6749&rtype=b_a&snippet=json|http://www.example.com/civicrm/contact/view?reset=1&cid=24068|2386||Error: Call to undefined method CRM_Contact_BAO_Relationship::isCurrentEmployerNeedingToBeCleared() in CRM_Contact_Form_Relationship->setEmploymentRelationship() (line 654 of /var/www/html/sites/all/modules/civicrm/CRM/Contact/Form/Relationship.php).
This used to work correctly and seems like it may have stopped working after 5.x upgrade, though the server was also updated about the same time.
Appreciate any ideas on how to resolve this