"Could not install the custom actions. The object could not be found." Error Starting Outlook

When you open any item in Outlook, you may receive one of the following errors:

"Could not install the custom actions. The object could not be found."

or

"Outlook cannot open this item. The object could not be found."

when you click OK to the error the item opens.

This problem can occur if either of the following are true:

• Your frmcache.dat file is corrupted
• You are missing one or more .cfg files from the following folder:

\Program files\Microsoft Office\Office12\Forms\1033

Note: The above path is for a US English install (1033). The folder you use will vary according to the language of Office you are using.

Outlook uses the .cfg files as the default forms for Outlook items and rebuilds the forms cache file with these .cfg files in most situations. If these .cfg files are missing then Outlook cannot create a new frmcache.dat file or repair a corrupted one.

Use one of the following methods to resolve the problem:

Method 2: Delete the frmcache.dat file and start Outlook

1. Exit Outlook.
2. In Windows Explorer, open the following folder (depending on your version of Windows):
   
   Windows XP
   
   C:\Documents and Settings\username\Local Settings\Application Data\Microsoft\Forms
   
   Windows Server 2003, Windows Vista, or Windows 7
   
   C:\Users\username\AppData\Local\Microsoft\Forms
   
3. Delete the Frmcache.dat file.
4. Start Outlook.

Method 3: Repair your Office installation.

For detailed instructions on installing and repairing Office, see the following Knowledge Base Article:

How to install the individual 2007 Office features or to repair the installed 2007 Office programs 
http://support.microsoft.com/kb/924611