An attribute database can get corrupted over time, if it happens the following message will appear each time coronerd is started:
[...] 2018-03-16 13:03:47Z [T0] [project_event:560] [ns /universe/project/crdb] Project's attributes crdb is corruptedBefore initiating the repair procedure, make sure you have a backup of the database (see https://help.backtrace.io/troubleshooting/how-do-i-create-backups-of-the-object-store) in the event that something goes wrong.
To start the recovery procedure, use morgue in the following way
morgue repair <[universe]/project>