It turned out that proper selection is key. I was using the SHIFT key to select one cloud folder node and another cloud folder node, which selected folders, and clouds among other things.
- The proper way was to press down the CTRL key while clicking on only cloud nodes in the tree view pane, as shown in the screenshot below. Once two cloud nodes have been selected, the File Align icon in the toolbar will become enabled.
The File Align icon is enabled.
- Click the Fine Align icon.
The Clouds registration dialog box appears.