Problem:
When you try to use the "out of office reply" option is Microsoft Outlook you receive the following error:
"The command is not available. See the program documentation about how to use this extension."
Resolution:
There are two ways to go about fixing this problem.
Method 1:
Inside Outlook, Click the "Help" menu, and then click on "About Microsoft Outlook. Then click on "Disabled Items." Select "outex.dll" and select enable. If this does not fix your issue then try method 2.
Method 2:
Close Outlook, Click Start Button, Click "run", Type "Regedit".
Browse to the following location: HKLU\Software\Microsoft\Office\11.0\Outlook\Resisliency
Right-Click on the "Resisliency" key and select export. Save the .reg file somewhere incase you need to import this later.
Now Right-Click on any sub-keys of "Resiliency" and select delete.
Now startup Outlook and you should be able to use your Out of Office Reply.
If this helped you fix your problem, Please email me and tell me about it.