@anon44759713 Please check out if the error also occurs in the course playground when you get a chance and let me know if you have any other questions or issues afterwards. Thank you!
Hey Im having the same problem as described above by the other user. I am also running Xcode 10 and I tried it both on the course playground and my own playground.
UPDATE: after googling it, the error seems to go away if the code its switched to run automatically instead of manually. Kept scratching my head for hours why my code wouldn’t work!