The OWA search function does not work for some users in Exchange 2007, how can I correct this?

Users receive the following error when performing a search in OWA 2007: "Search results may take a long time to appear because Microsoft Exchange Search is unavailable. Results will not include matches in the e-mail body". Additionally, running the test-exchangesearch command against the user's mailbox does not find any search results.

In this scenario, the full-text index catalog is corrupted and must be rebuilt using the ResetSearchIndex.ps1 script. For more details, refer to the Microsoft Knowledgebase Article 945077: The Outlook Web Access search function does not work for some users in Exchange 2007.