TF20017: The area or iteration provided for field 'Iteration Path' could not be found.

When attempting to update a TFS work item I got the following error prompt:

To add the new iteration from the menu: Team > Team Project Settings > Areas and Iterations...

Then jump to the Iteration tab and use the "Add a child node" button.

Refreshing the TFS cached iteration list

1. Close Visual Studio to release any file locks in the cache.
2. Delete all the files in:
   

   C:\Documents and Settings\[USER]\Local Settings\Application Data\Microsoft\Team Foundation\2.0\Cache

   or
   

   C:\Users\[USER]\AppData\Local\Microsoft\Team Foundation\2.0\Cache

   depending on your OS.