Apply filter > Lighting effects to an image (300 ppi RGB) and when photoshop renders the lighting, there is a horizontal line through the image. It is not a screen or video issue, it is in the image and has to be retouched out like corrupt image.
not a transparency issue, tried different file formats, flattened image first, etc.
Had this happen before, but now in Cloud V6 is really aggrevating. People have been posting about this for at least 3 versions with no answers.
Moved from the Creative Cloud to the Photoshop forum. They will be able to help you here.