Jupyterhub 404:Not Found... all of a sudden with no changes to server?

I installed jupyterhub from these directions, jupyterhub-the-hard-way/installation-guide-hard.md at 35ddfb49ad81771551c6549696ccec960564d5e4 · jupyterhub/jupyterhub-the-hard-way · GitHub, super easy, and been working great for a couple months. All of a sudden I’m getting “404:Not Found” logging into jupyterhub?

I haven’t changed anything, I haven’t even updated the server.

If I comment out the ‘/lab’ line in the config I can restart and access Jupyterhub.
c.Spawner.default_url = ‘/lab’

But jupyterlab(I’m guessing) doesn’t work. I don’t understand why it all of a sudden stopped working when nothing changed on the server I haven’t even updated the server.

Is there anything I can do to get Jupyterlab to start working again?

Well, that was easy, force reinstalling jupyterlab started it all working again… no idea why it stopped working.