mcr.microsoft.com/devcontainers doesn't exist?

[Is0metry]

I'm trying to get started with dev containers for a project, but I'm running into this issue and it's pretty inexplicable. It seems that https://mcr.microsoft.com/devcontainers is missing entirely.
I've tried multiple different Python and general templates, all of them seem to use a template linked to the MCR, and all of them end up with the below error:
Error response from daemon: No such image: mcr.microsoft.com/devcontainers/<image endpoint>
Navigating to the actual endpoint in Chrome yields the following screen:

(this is from the base endpoint, but occurs across all the different templates)
I'm not convinced I haven't made a rookie mistake in all of this, or that Microsoft may be having their own issues, but given that I've been able to get started with these images in the past from my current setup before, and I can't find any discussion of this anywhere else, so I'm hoping that someone here will be able to provide a good explanation. Thank you very much in advance!

Update: Searching MCR seems to turn up some development images, but they link to the same dead endpoints. (e.g. I was able to find the Anaconda artifacthere). Keeping discussion open, as I don't know of a better way to get this information to those who may be able to remedy it.

[Is0metry]

Closed as it was a docker issue. Sorry for any confusion!