Using the old editor, which is probably the case here, it is very cumbersome to copy over screen pages. When you insert an image or text Guide will give it an ID in the form of a number that is assigned sequentially as you save the images. In order to copy over a screen from another .scs file the images need to be saved in your new program in the exact same sequence so they have the same ID number. This becomes a problem if the screen you want to copy has images starting at a high number with possible gaps in the order they were saved. So if your screen uses image IDs 24,25,26,30, and 38 you would need to save at least 23 images before you get to the proper ID and also make sure you have 3 images to bridge the 26-30 gap and another 7 for the 30-38 gap. If you have programs like mine then your screen could have images contained in the hundreds.
Long story short is if you have a large program you will probably be quicker to just make the screen pages again from scratch. If you have two programs that are very similar it may be quicker to save the program as a new name and then modify what needs to be changed.
Now the light at the end of the tunnel is that Sauer-Danfoss finally updated their editor and the new editor now saves the images using text as the ID so as long as the images are saved under the same name you should be able to copy a screen from one .scs to another.
