There is weird bug in the focus stacking function of version 24.5 of Photoshop. It's the one where you load a number of focus stacked images into layers, then let Photoshop automatically merge these layers, by picking the image parts in focus out of each image of the series.
With this bug the output image contains a set of transparent rectangles in the middle of the image. These extend from one side of the image to the other.
I've now reverted to version 24.4.1 which does not have this problem.
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