4. Drag the Identities folder to the Privacy window. This adds the folder to the Privacy list, which means Spotlight will not search this folder in the future. But this is not your goal. You want the opposite. So…

5. From the Privacy window, select the newly added Identities folder. Then click the minus (-) button near the bottom left of the window. This removes the folder from the list.

On the surface, this appears to have accomplished nothing; you just undid a change you made a moment before. However, it should the Identities folder. If there was a problem with Spotlight and the data in this folder, the re-index will hopefully fix it. This worked for me.

You can track the progress of re-indexing by selecting the Spotlight menu bar item. The reindexing time should be relatively brief in the above case. However, if the time appears so brief that you suspect no re-indexing was done at all, and if the search problem thus remains, you can force a re-index of your entire drive. To do so, launch Terminal and type:

sudo mdutil -E /