引用自 Lord Strong：

i think i did it right but got stuck here.

Hey! Would you be able to share screenshots/a video of what the issue is? Thanks :)

If you are still having the problem pls read the msg a second time. most of the time the error is that you can't fill something in and you should reposition the container. and not that the container is already full.
Hardly missleading, but can be easily worked around.