Quick tip:
If you have a DAG with a ContentIndexState showing failed, you can fix it with a simple command in the Exchange Management Shell (EMS):
- Update-MailboxDatabaseCopy -Identity “DAGNAME\store” -CatalogOnly
This will then start a re-seed and it should return to a healthy state once complete.
![Exchange 2010 and higher:- fix a dag's contentindexstate that failed Exchange 2010 and higher:- fix a dag's contentindexstate that failed](https://everything-powershell.com/wp-content/uploads/2019/09/image-6.png)