Topic Last Modified: 2007-01-23

The Microsoft® Exchange Database Troubleshooter Tool detected one or more MSExchangeIS 9518 events with error code 0xfffff764 in the Application log. This error can occur if Exchange is unable to access the streaming file (.stm) that is associated with a database.


This error can occur if the streaming file (.stm) that is associated with a database has been deleted, moved, or if Exchange cannot access the streaming file because of a permissions change.

Under certain circumstances, antivirus programs can delete or change the permissions on Exchange files, including the .stm file, if you have not excluded the Exchange directories from scanning per Microsoft Exchange best practices. For more information about this topic, see Microsoft Knowledge Base article 823166, Overview of Exchange Server 2003 and antivirus software.

This error can also be identified as -2204. This error applies to the following versions of Exchange server:

  • Microsoft Exchange Server 2003

  • Microsoft Exchange 2000 Server

User Action

To resolve this issue, do one or more of the following:

  • Restore the streaming file from a backup copy of the database.

  • Check whether your antivirus software has moved the streaming file to the Quarantine folder. If the file is in the Quarantine folder, move it to the original location, and then configure the antivirus program so that it does not scan the Exchange Server 2003 folders.

    Some antivirus programs change the file properties to Read-only when the files are moved to the Quarantine folder. If you find the streaming file in the Quarantine folder, right-click the file, and then click Properties. Click to clear the Read-only check box before you try to mount the database.
  • You can run the Microsoft Exchange Database Recovery Management Tool that is part of the Microsoft Exchange Troubleshooting Assistant. The Database Recovery Management Tool can analyze the database and transaction log files for this storage group and give you additional details about the issue. For more information and to download the tool, see Microsoft Exchange Troubleshooting Assistant v1.0.