"can't transform pixels because the selected area is empty"

I don't want the Clone-Stamp tool.  I was referencing that as a tool that I had successfully used previously by creating a new layer above the Smart Object and doing the edit in that layer.  The tool I am trying to get to work is Edit>Transform>Skew and what I am trying to do is skew a selection in a Smart Object downwards.  My assumption was that I needed to do this in a new layer created above the Smart Object but that seems not to be the case.  I went into the Smart Object Layer; hit Ctrl T; and then selected Edit>Transform>Skew.  I was able to to grab the middle square on the grid and drag the right side of the tile border downwards.  So it appears there are certain effects you can create on the Smart Object layer (this one) and others you can't (the Clone/Stamp).  I don't understand the rationale behind the difference but perhaps will someday.  Thanks.

Thank you for your reply.  I have pasted an image of the Layer in question with all other Layers turned off.  As can be seen, the tile border is at the bottom right corner.