Coolscan 4000 is not in the list of supported cameras :)
Generally, files from Scanners should be 3-component, not bayer-pattern. So, camera-targeted NEF-handling code will not work with scanner files because only one per-pixel component is expected.
BTW, if you provide any sample of Coolscan .NEF output, it will be analyzed in depth. May be, it is easy to add support for these files to LibRaw
Coolscan 4000 is not in the list of supported cameras :)
Generally, files from Scanners should be 3-component, not bayer-pattern. So, camera-targeted NEF-handling code will not work with scanner files because only one per-pixel component is expected.
BTW, if you provide any sample of Coolscan .NEF output, it will be analyzed in depth. May be, it is easy to add support for these files to LibRaw