I've been trying to play through the tutorials, and I'm stuck at the beginning of the Basic Logistics tutorial. It asks me to create a defence platform, which I duly do. However, upon completion of it I can't get to the next stage of the tutorial - it seems to not recognise that I have completed the building. I've tried exiting, starting a new tutorial, and then going back in but to no avail. Any suggestions as to how I might avoid this problem?

EDIT: Never mind, I somehow managed to get it to work by randomly building other things, feel free to delete this thread mods!