Does the 3d window (opengl) show the cut elements as black?
If so, it must be that your MATERIAL definition does NOT match between INTERNAL ENGINE and LIGHTWORKS..
Please note that there is a pull down tab for every material that lets you define the attributes individually between Internal, OpenGl and Lightworks.. Often, materials show differently when you don't want them to..
So first, hit the MATCH INTERNAL ENGINE button while in the Lightworks section of your material definition... Look at the PREVIEW sphere.. It's also likely that LIGHTWORKS add a bunch of REFLECTION which will send your rendering into the WHITE mode as the sun is likely high in your sky. Use the editor dialogs to achieve a more true black (for example, change MIRROR to flat shading or something like that.)....
If all else fails and you can save an ARCHIVE... I'm happy to take a look at it...
Duane
Visual Frontiers
AC25 :|: AC26 :|: AC27
:|: Enscape3.4:|:TwinMotion
DellXPS 4.7ghz i7:|: 8gb GPU 1070ti / Alienware M18 Laptop