Layer mask not working

[Shivani-H]

Hello when I select a layer mask I can't see the shading on the actual picture only on the mask itself (I.e. the small white rectangle) what am I doing wrong?

[JJMack]

Please post a screen Capture so we can see what you are looking at. Layer mask changes the visibility/opacity of pixels in the layer.   You can also displays a layer mask as a grayscale.  By shading do you mean layer pixels opacity with lower layers pixels blended in?

Also if your using 21.2 make sure Legacy Compositing is not checked in your preferences performance section.  Adobe broke that in 21.2

[Shivani-H]

Hi JJmack, sorry for the blurred pic - but if you can see on the layer mask it shows areas of black and white but on the picture it hasn't masked anything so I don't know what's going on or how to apply the mask 

[JJMack]

You should post as screen capture not whatever you posted here.   However in what you did post I see a visible layer  above the layer with the layer You may not be able to see any effect the layer mask add to the composite the upper layer could be covering all the effect the layers mask added.  From what I see in the layer thumbnail the content of the layer covers the canvas. The Layers is not targeted but if it was I would not be able to make out its blend  mode, opacity and fill with what you posted.  In the future please post screen captures.  Its not always possible to tell what the layer mask does if you cover the layer. See here:

[Shivani-H]

Hello - I think I have solved the problem. Thank you for your help!

[Gary GDS]

Thank you JJMack. Unchecking legacy compositing fixed this for me.