Strange 404 error when booting ship for first time

[Christopher King]

I'm seeing the following error when trying to boot a ship for the first time:

error fetching http://eth-mainnet.urbit.org:8545: HTTP 404

I've never seen this before. What is happening?

[Christopher King]

For posterity, since this happened to get diagnosed and discussed outside of this mailing list: turns out this was the same issue identified here and here. Matilde reached out to the ops team and had the proxy reset. H/t to Anton as well for pointing me in the right direction in the first place.