bucket error "Leaving it in PendingDiscard state."

I'm looking for documentation about the following error:

"Discarding bid=foo~0~60F537A5-5D22-4F24-81FD-000544991297 on peer=8E98E68C-5240-4298-9B79-AAFC9C42B2A7 failed. Leaving it in PendingDiscard state."

The error appears on the manager UI in clustered splunk 5.0.3 for a clustered bucket

Thank you!