about "nightmare secenario" and raider wars....
You may my solution:
- download the vp-viewer (see freespace tools section at
http://homepage.ntlworld.com/karajorma/FAQ/intro.html for a link)
- download the raider wars patch 2.1 (or newer)
- open the *.vp-file of the patch and extect the files from it into you "[TBP-Foder]\data\missions\"-foder
- rename the mission files to unlink them from the campaign file (links to sound-files etc. stay intact)
- play them via tech room
ruins the campaign-feeling as you can scip mission you don't win and needn't to play them in correct order but allows you to skip nightmare sceanrio (which is not working on my side too)
you may build a new campaign tree or rename it and fill it with the renamed mission files in order to fix it -> allows ypou to play it as campaign but you need to know how it's done