Error when attempting to disable Out of Office Assistant.

 

Summary

Occasionally, when someone is attempting to disable their Out of Office Assistant in Microsoft Outlook, they will receive the error...
"This command is not available. See the program documentation about how to use this extension."

Contents
Error when attempting to disable Out of Office Assistant. Summary Issue Solution

Issue

For one reason or another, the extension was disabled the last time they shut down outlook.

Solution

1) Go to the Help menu
2) Drop down to About Microsoft Outlook.
3) Click on Disabled Items in the bottom right.
4) Select the "outex.dll (outex.dll)" file out of the listing and click Enable.
5) Close and re-open outlook.

A user of Outlook 2003 reported that when she wanted to turn off an out-of-office message she had previously set, she received the message below.

Microsoft Office Outlook

The command is not available. See the program documentation about how to use this extension. [ OK ]

When I sent test messages to her I didn't see any out-of-office replies.
Microsoft has a Knowledge Base article on the problem "You receive an error message when you try to start the Out of Office Assistant in Outlook 2003". That article recommends ensuring that no Outlook process is running and then checking the HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook registry key for a Resiliency subkey and, if it exists renaming it to Resiliency.old. A similar Knowledge Base article, Article ID 327353 recommends the same procedure if the problem occurs under Outlook 2002, though the registry key references 10.0 rather than 11.0 as the Outlook version. I don't know why Microsoft recommends renaming the Resiliency key rather than deleting it. There is no statement about restoring the orginal name afterwards. Perhaps Microsoft is suggesting renaming it in case deleting it doesn't resolve the problem or creates some other problem. There doesn't seem to be any reason for retaining the renamed subkey if renaming it removes the problem and Outlook works fine afterwards.
I did see a Resiliency subkey in the registry on the user's system. But in trying to understand the function of that subkey, I found another solution based on comments at Outlook / Disabled Items / Resiliency. The solution I employed was based on the information provided at that webpage. Since the solution doesn't involve editing the registry it is a procedure that can be employed by a user without risk of inadvertent damage to the registry.
To resolve the problem, you can take the following steps:

1. Open Outlook.
2. Click on Tools.
3. Click on About Microsoft Outlook.
4. Click on the Disabled Items entry.
5. You will see a Disabled Items window open, with the following information within it:
   
   

   The items below were disabled because they prevented Outlook from functioning correctly.
   
   Please note that you may have to restart Outlook for these changes to take place.
   
   Select the ones you wish to re-enable.

   
   If you see "Addin: outex.dll (outex.dll)" listed, click on it to highlight it and then click on the Enable button. Then click on the Close button. Then click on the OK button to close the About Microsoft Office Outlook window.

You should then be able to click on Tools and then Out of Office Assistant to modify the out of office setting.
When I employed the procedure and then checked the registry afterwords, there was no longer a Resiliency subkey. The outex.dll DLL, which is apparently used by the Out of Office Assistant, was the only disabled item. The key that had been in the registry is listed below:

The source of the problem is suggested on Josh Einstein's Web Log as being due to Outlook permanently disabling an addin:

If the AddIn experiences a problem during initialization, Outlook will prompt the user that the AddIn caused a problem and would you like to disable it. The user will of course always choose “yes” and this is where the problem starts.

Outlook creates a new item in HKCU\Software\Microsoft\Office\11.0\Outlook\Resiliency\DisabledItems that contains some cryptic hashed value of your AddIn. If your AddIn is listed here, forget about it! Outlook will not load it again. You can remove and reinstall the application as much as you like but that key never gets overwritten so the AddIn never gets loaded.

[HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\outlook\Resiliency]

[HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\outlook\Resiliency\DisabledItems]
"437C9368"=hex:01,00,00,00,14,00,00,00,14,00,00,00,6f,00,75,00,74,00,65,00,78,\
  00,2e,00,64,00,6c,00,6c,00,00,00,6f,00,75,00,74,00,65,00,78,00,2e,00,64,00,\
  6c,00,6c,00,00,00