First of all, thanks to the GoG-team for providing the German 1993 Floppy Disk Edition of "X-Wing". :)

It looks like the B-Wing Expansion missions and cutscenes are inaccessable. No descriptions are shown and trying to play these missions result in a crash.

But I've found the problem and fixed it:
-BWING.CFT is missing in the RESOURCE folder
-TITLE.LFD and MISSIONS.LFD inside the RESOURCE folder are the wrong versions for some reason

If the GoG-team could fix the issue, I and many others would be very grateful.

Oh and I'm also looking forward to have X-Wing CD (1994), TIE Fighter Floppy (1994) and X-Wing vs TIE Fighter in German next. :)

Try contacting support and/or JudasIscariot If you have the floppy versions at your hands you can try contacting GOG and ask if they want them.

Both has already happened ;)