Hello @azhar Nasim ,
Based on the information you provided, it is first recommended that you verify that the Microsoft Search (Exchange) service and the Exchange Host Controller service are running well on the server. You can check the status of a service using the PowerShell cmdlets.
Get-Service | Where-Object {$_.Name -eq "MSExchangeFastSearch"} | Select-Object Name, Status
Get-Service | Where-Object {$_.Name -eq "MSExchangeServiceHost"} | Select-Object Name, Status
These commands will display the name and status of the Microsoft Search (Exchange) service and the Exchange Host Controller service. If the status is "Running", then the service is working properly. If the services are not running, you can start them.
Besides, please use the following command to check the content index of the database copy:
Get-MailboxDatabaseCopyStatus *| select name,status,contentindexstate|Sort-Object name
For more information, please refer to Get-MailboxDatabaseCopyStatus.
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