Can't add `General` registry

I updated Julia from 1.11.8 to 1.11.9 this morning, and then tried to update an environment, but I got a 404 error from the package server. I also installed the most recent 1.12 release through juliaup and got the same error when running ]up.

Julia 1.11.9

 Updating registry at `C:\Users\johnb\.julia\registries\General.toml`
┌ Error: Some registries failed to update:
│     — C:\Users\johnb\.julia\registries\General.toml — failed to download from https://pkg.julialang.org/registry/23338594-aafe-5451-b93e-139f81909106/2af0b9e846fff196e81025db217fd0c934cf0b34. Exception: RequestError: HTTP/1.1 404 Not Found while requesting https://pkg.julialang.org/registry/23338594-aafe-5451-b93e-139f81909106/2af0b9e846fff196e81025db217fd0c934cf0b34
└ @ Pkg.Registry C:\Users\johnb\.julia\juliaup\julia-1.11.9+0.x64.w64.mingw32\share\julia\stdlib\v1.11\Pkg\src\Registry\Registry.jl:546

Julia 1.12.5

Updating registry at `C:\Users\johnb\.julia\registries\General.toml`
┌ Error: Some registries failed to update:
│     — C:\Users\johnb\.julia\registries\General.toml — failed to download from https://pkg.julialang.org/registry/23338594-aafe-5451-b93e-139f81909106/2af0b9e846fff196e81025db217fd0c934cf0b34. Exception: RequestError: HTTP/1.1 404 Not Found while requesting https://pkg.julialang.org/registry/23338594-aafe-5451-b93e-139f81909106/2af0b9e846fff196e81025db217fd0c934cf0b34
└ @ Pkg.Registry C:\Users\johnb\.julia\juliaup\julia-1.12.5+0.x64.w64.mingw32\share\julia\stdlib\v1.12\Pkg\src\Registry\Registry.jl:574

I found a thread from a long time ago (2018) that suggested deleting .julia/registries/, but given how long ago it’s from, I’m hesitant to follow that advice.

When I check the url from the error messages, it returns 404 in my browser as well.

I have never seen this error before. Is it happening for other people as well, or is there something wrong with my installation?