Not sure what the cloning layers are doing...but if they are destructive layers that use merged layers from below, they will not transfer to a different file. Curve layers will be OK. If there are masks, make sure the pixel dimensions are the same on both files. I have also found that in order to get the masks to transfer properly, the receiving file needs to be zoomed out really small and the dragged layers are let go at a distant outside the canvas of the receiving files. Otherwise the mask does not register properly. I have no idea why.