Adding and Editing Tags not working on Manage Case screen

Regression bug from 3.2 betas. You can no longer either add or remove tags from the Manage Case screen - Tags pane (CaseView). Replicated on demo.

To recreate:

• add one or more Tags: Used For = Cases
• navigate to an existing case
• click Add Tag in Tags pane
• select a Tag and click Save
  The page reloads, but the tag assignment is not saved (doesn't show on screen and isn't inserted in entity_tag table)