OL97: ErrMsg in Extension Configuration File Starting Outlook

When you attempt to start Microsoft Outlook 97, you may receive one or all of the following error messages:

The above errors result from either a damaged or missing .ecf or .dll file, or incorrect information in the Extend.dat file.

To correct this problem you may have to replace the damaged extensions, or you may have to remove the reference to them in the Windows Registry. If the problem persists, you should rename and recreate the Extend.dat file, which is a binary cache of extension settings.

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall Windows 95. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the Changing Keys And Values online Help topic in Registry Editor (Regedit.exe). Note that you should make a backup copy of the registry files (System.dat and User.dat) before you edit the registry.

To Replace the Damaged Extensions

1. Close Outlook.
2. From the Office\Addins, directory of your Outlook setup medium, copy the problem .ecf file(s) referenced in the error message, over the exiting files, usually found in, Program Files\Microsoft Office\Office\Addins.
3. Restart Outlook.

Removing Registry Entries

1. Quit all programs.
2. On the Windows Taskbar, click Start and then click Run.
3. In the Open box type, regedit.exe.
4. Navigate to the folder:

      HKEY_LOCAL_MACHINE\Software\Microsoft\Exchange\Client\Extensions
   						

5. You will see the add-ins listed on the right under the heading of "DATA." Click to select the name of the Data key that corresponds to the file in the error message and press DELETE to delete this registry key.
6. On the Registry menu, click Exit.
7. Restart your computer and then restart Outlook.

Refreshing Extend.dat File

If you still receive the error message when you restart Outlook you must refresh the Extend.dat file, which is a binary file that caches the registry extension entries.

Follow these steps to refresh the Extend.dat file:

1. Quit all programs.
2. On the Windows Taskbar, click Start and then Find and Files or Folders.
3. In the Named box, type extend.dat.
4. In the Look in list, click to select your hard drive.
5. Click to select Include subfolders and click Find Now.
6. In the Name list, right-click on the file Extend.dat and on the shortcut menu, click Rename to rename the file to Extend.old.
7. On the File menu, click Close to exit Find File.
8. Restart Outlook. Restarting Outlook recreates a new Extend.dat file.

For additional information about this error with Schedule+ Files, please see the following article in the Microsoft Knowledge Base: