cloudresourcemanager.projects.list returns 404

[stephenplusplus]

To reproduce, try executing the API Explorer demo without arguments:

https://developers.google.com/apis-explorer/#p/cloudresourcemanager/v1beta1/cloudresourcemanager.projects.list

Monitoring the outgoing requests from the dev tools, it requests the following URL which returns a 404:

https://content-cloudresourcemanager.googleapis.com/static/proxy.html?jsh=m%3B%2F_%2Fscs%2Fapps-static%2F_%2Fjs%2Fk%3Doz.gapi.en.JZCw1sZyr38.O%2Fm%3D__features__%2Fam%3DEQ%2Frt%3Dj%2Fd%3D1%2Ft%3Dzcms%2Frs%3DAGLTcCNsFuPdAI16TyKAffH5jIkdIAOE8Q

I encountered this while using this JS library to access the resource manager API, but it failed locally with the same error. That prompted me to try the API Explorer, where I was surprised to find the same behavior. Thanks for any help!