Unless you have all the stock Lightning files in the Original Files folder then it would be correct to not work. Keep in mind our software doesn't come with any tunes (stock or modified). It's only designed to modify files that are read from the vehicle (or files that have been emailed).
When you open Special Forces and choose "Start a new tune", you're typing in CUX2 for the computer box code? If so and you're still getting the error message then you need to check a few more things.
1. Make sure the stock file I emailed you (or any other stock file you may have) is in the "Original Files" folder
2. Make sure the "Original Files" folder is in the Delta Force Tuning folder
3. Make sure the stock file is the correct size (112kb, 224kb, 448kb, 531kb, 1024kb). For the Lightning it should be 224-225kb
4. Make sure you're typing in CUX2 for the computer box code of the file I sent you in the SF software
5. Make sure the required template is in the "Templates" or "TRM Files" folder. It should be MRAD3.tmpl
Director of Sales & Marketing