The upgrade over the weekend removed JupyterQ/embedpy as PyKX can be configured to replace it now.
If you ‘git pull’ the project, or reopen the sandbox link from the course page, it should resolve its-self. The problem may be that the upstream changes can no longer be merged into your local copy so may need some manual intervention. A quick fix would be to move the existing course project (with your existing work) to the side by renaming it and then refetch the project with the sandbox linky as usual.
On a related note, for your own notebooks, select ‘Python 3 (ipykernel)’ as your kernel make the first cell contain:
#;.pykx.disableJupyter()
The second cell contain:
# https://code.kx.com/pykx/3.0/examples/jupyter-integration.html#q-first-mode
import pykx as kx
kx.util.jupyter_qfirst_enable()
Then it should behave just like the previous JupyterQ/embedpy kernel.