Usually these types of messages are due to something simple. However, even for experienced designers, it is sometimes hard to immediately work out what the problem is. The message, 'could not move the selection because the selected area is empty' can happen when a selection has been made on a blank or empty Photoshop layer and an attempt has been made to use the move tool.
For example, this message might appear when a user has made a selection and is intending to move an element on a layer, but has unintentionally selected an empty layer. That is, a layer which has no pixels or other image data on it.
A similar warning might appear when trying to make a new layer from a selection. For example, on the right, the designer wanted to use a section of the image on Layer 1 to create a new layer. However, they did not notice that they inadvertently had the empty Layer 2 selected in the Layers palette.
When the user typed Command + J on their Mac, to copy the selection and create a Layer via Copy, they received the following warning message 'could not make a new layer from the selection because the selected area is empty. When they subsequently changed the layer selection to Layer 1, they were able to successfully create the new layer from the selected area. For good measure they deleted the empty layer to save confusion later on.