The project.scrivx can be deleted–it’s from the previous version of the tutorial–but really I’d just replace the entire “Tutorial.scriv” in your installation folder with the one I attached earlier. The problem here seems to be that installing over the existing version caused the new version of the tutorial to merge with the old one, so that project.scrivx file isn’t the only lingering thing in there. It may not be a problem otherwise to the project functioning, but better to have a clean copy.
In fact, here: I’m attaching the tutorial project again. It’s even better than the one packaged with 1.9, 'cause I fixed a stupid mistake I made in the one that’s part of 1.9. 
Tutorial-1_9.scriv.zip (1.84 MB)