Stage renderer on the Idea table list view is broken and the UI actions Accept and Defer are not visible

All releases

The state value is not 1 ("Submitted")

1. The buttons and stages are correctly displayed for an idea record only if the record's state is Submitted
   2. In OOB, the state field has a default value of 1 ("Submitted") but in your instance, the default value might be empty. Check the Default tab here https://<instance_name>.service-now.com/nav_to.do?uri=sys_dictionary.do?sys_id=fb4602424f320200273ef7e18110c7cf
   3. You may update the default value to 1, OR 
   4. If this is against your business process, you may create a dictionary override for the state field in the Idea table and update the default value to 1 only for that table.