Our environment consists of a single Exchange 2016 CU8 server and multiple clients using Outlook and OWA.
Searching (fast search and advanced find) both are not working in either OWA or Outlook desktop. The results are simply empty with "no items found."
Additional weird symptoms:
MSExchangeFastSearch is throwing the following in Event Viewer:
An operation attempted against a FAST endpoint exprienced an exception. This operation may be retried. Error details: Microsoft.Exchange.Search.Fast.PerformingFastOperationException: An Exception was received during a FAST operation. ---> System.ServiceModel.FaultException: Could not load file or assembly 'Microsoft.Exchange.TransportFlowMdm.105, Version=1.0.0.0, Culture=neutral, PublicKeyToken=0fbbedb750799a68' or one of its dependencies. The system cannot find the file specified.
And when checking on the database content status of the newly created DB:
ContentIndexState : Unknown
ContentIndexErrorMessage : Could not find registry value of Index Status for database
{3c0560f8-3c41-45cc-b176-823123ba9e26}.
Steps I've tried:
1) Rebuilding content index (now it shows "healthy"
2) Moving mailboxes to new database
I'll be upgrading to CU9 over the weekend as a last-ditch effort. Anyone have ideas?
Best Answer
First, please ensure the Microsoft Exchange Search and Microsoft Exchange Search Host Controller services are running. Then, after rebuilding the content index state of the database, we can wait for some hours to search again and check if any helps. Moreover, please also run the following command to check if the content index state of other databases are healthy: