Hi, I had the same problem you did and traced it back to a faulty line in loader.c (which contains makelx's main()). In revision 1.3 and earlier of that file you can find the following toward the end of the file: if(argc-optind<3 || lx.text_size==0) (...) (23 years ago, 15-Nov-01, to lugnet.robotics.rcx.legos)
