To resolve, this part must be cut from the page and a new part inserted.

To cut the part:
  1. Navigate to Site Explorer>Pages & Template
  2. Search for the page that is having the error
  3. Click on the page name to select it
  4. The associated parts will show in the lower pane
  5. Locate the part called Transaction Manager part and click the Scissors icon to cut
From here, a new part should be created and added to the page.