Thank you for the tip about the additional information in another part of the literature and the explanation of the thread path. We have threaded and re-threaded the machine, and we are 99% certain now that it isn't a threading problem. Our needle won't come back up. The machine just won't sew. We can engage Quilt Path, and the machine will follow the pattern, but the needle won't move up and down. The needle also won't move when we try free motion either. It doesn't seem to matter whether Quilt Path is used or not.