To resolve the error, follow these steps:
Inspect the Application log on the server that reported this event for Warning or Error events associated with the Microsoft Exchange Information Store (MSExchangeIS). The event description will indicate that the Exchange VSS Writer encountered a problem performing a specific task. Examine these events to determine the extent of the problem.
Contact your backup application vendor if you need help.
If you are not already doing so, consider running the tools that Microsoft Exchange offers to help administrators analyze and troubleshoot their Exchange environment. These tools can help you make sure that your configuration is in line with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. Go to the Toolbox node of the Exchange Management Console to run these tools now. For more information about these tools, see Toolbox in the Exchange Server 2007 Help.