D&D a Button into the Content Panel.
Drag the Button from the Hierarchy panel to the Content Panel (shows illegal move cursor) - Bug - Button shown as selected in Hierarchy but no selection shown in Content Panel.
Release the Button while mouse inside the Content Panel - Bug - Button still shown as selected in Hierarchy but no selection shown in Content Panel.
Select the root container in the Hierarchy - Bug - No selection shown in Content Panel.

It could be expected that the user will encounter this bug by trying to re-parent by dragging from the Hierarchy and dropping in the Content Panel. Perhaps this is a feature we should support? Anyway for now, we should fix the loss of selection in 1.1.