Selecting tonal range - nothing happens

[Shoogles]

Hi,

I'm not sure what I"m doing wrong.  I've created a new pixel layer, ensured it is selected and then clicked Select > Tonal Range > Select midtones.  And nothing is selected.  The same applies if I try selecting highlights, or a colour range.  

What's my mistake?

[HVDB Photography]

Hard to say without a screenshot !

Layer > New Layer just creates an empty layer, so no midtones available.

Dragging or placing an image into AP creates an image layer that first need to be rasterised
(right click on the layer and choose Rasterise)
 

[Shoogles]

Thanks HVDB.  I hadn't realised that I needed to select the background pixel layer for this.  It's my ignorance about what a pixel layer actually as (together with whatever rasterising is!) that's part of the issue.