When you use Outlook Web Access (OWA) in light mode in a shared mailbox in an Exchange Server 2010 environment, you cannot run a search, and you receive the following error message:

Your request couldn't be completed. This may have occurred for security reasons or because your session timed out.

Additionally, the following error is logged in the Application event log:

Exception: Type: Microsoft.Exchange.Clients.Owa.Core.OwaInvalidCanaryException Error: Invalid canary in search query.

Note This issue occurs only in Update Rollup 15 and Update Rollup 16 for Exchange Server 2010 Service Pack 3.


This issue occurs because the canary parameter is not added correctly in the search request.


To fix this issue, apply Update Rollup 17 for Exchange Server 2010 Service Pack 3.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.


Learn about the terminology that Microsoft uses to describe software updates.

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