Symptoms

All types of content cannot be created or edited.

The following appears in the atlassian-confluence.log:

Cause
org.springframework.dao.DataIntegrityViolationException: Hibernate operation: could not insert: com.atlassian.confluence.mail.notification.Notification#35946524;
 SQL []; ERROR: duplicate key value violates unique constraint 
"notifications_pkey" Detail: Key (notificationid)=(35946524) already 
exists.; nested exception is org.postgresql.util.PSQLException: ERROR: 
duplicate key value violates unique constraint "notifications_pkey" 
Detail: Key (notificationid)=(35946524) already exists.

Diagnosis

Try to disable Autowatch in your user profile. If that allows you to create a page in a fresh space, then this KB is applicable to you.

Cause

There is a rogue notification row in the NOTIFICATIONS table in the Confluence Database, highlighted in the log (in this example, 35946524).

Resolution

• Shutdown Confluence

• Take a backup of the Confluence Database, then run the following query to remove those rogue notifications rows.

  DELETE FROM notifications WHERE NOTIFICATIONID = <ID>;
  

  Replace <ID> with the ID highlighted in the logs. In the log snippet above, the ID equals to 35946524

• Startup Confluence