~Possible corrupted index on EventQueueEntry table.
1. Truncate the EventQueueEntry table.
2. Rebuild its problematic Clustered index:
ALTER INDEX [PK__EventQue__3214EC071E6F845E] ON [dbo].[EventQueueEntry] REBUILD PARTITION = ALL WITH ( PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, ONLINE = OFF, SORT_IN_TEMPDB = OFF )
3. Cut all the NSE files from the EventQueue folder into the EvtInbox folder.
4. Watch the files being moved back to the EventQueue folder and processed.