You want to start an operation on a dialog like “My Computer”. But you see that the necessary controls are not available.
Usually the reason for that is quite harmless. You may have started a wizard like “Create backup job” or “Create single backup”.
These wizards will create the tabs “Create backup job” resp. “Create single backup” at the bottom.
As long as the wizard is open you are able to switch to other tabs. But you cannot enter anything and have no handling controls because the wizards are blocking anything.
To be able to execute other operations please first complete or cancel the respective wizard in the foreground.
Subsequently any operation will be possible again.