Symptoms
In a Microsoft Exchange Server 2019 or Exchange Server 2016 hybrid environment, when you try to use the Exchange admin center (EAC) to copy eDiscovery search results for mailboxes that have Exchange online archives in Office 365, you receive the following error message:
Failed Search or Export, Mailbox:<MailboxAddress>::Item:::DocumentId:::ItemId: with error: [FailedToSearchMailboxes] Export failed with error type: 'FailedToSearchMailboxes'. Message: Response from the EWS endpoint 'https://outlook.office365.com/EWS/Exchange.asmx' contained invalid preview results. Invalid value was returned for sort value in one of the preview items.
Resolution
To fix this issue, install one of the following updates:
The Cumulative Update 3 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019.
The Cumulative Update 14 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016.
References
Learn about the terminology that Microsoft uses to describe software updates.