...
To Rebuild LUNA Viewer Index using the Collection Manager, open the Collections tab and select the collection you want to rebuild. Click the Rebuild LUNA Viewer Index at the top of the page.
Next, you will be presented with a dialog box. To continue with the process of rebuilding the LUNA Viewer index click the Refresh button.
The following message will be displayed as the Viewer index is being rebuilt. Click the Close button to exit the dialog box.