could not resolve error occurring sometimes

I am sometimes getting a “could not resolve” error with the notebook

Refreshing the page and clearing cache sometimes helps. I also have this fork of the notebook that does not have the same issue

The notebook makes several GET requests from different resources (Biorxive, GitHub, Google sheets), computes a word cloud, and renders a table.

Hi @cornhundred,

I’m not seeing a “could not resolve” error when viewing the first notebook. Can you share a screenshot of the error and/or the cell in which it occurs the next time it happens again?

Thanks @jashkenas, I attached a screenshot of the error (which only happen somtimes):

Here’s the error message that appears CORS related:

Access to fetch at '' from origin '' has been blocked by CORS policy: The 'Access-Control-Allow-Origin' header has a value '' that is not equal to the supplied origin. Have the server send the header with a valid value, or, if an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

In other parts of the notebook I’m using to get around non-CORs supported APIs. So I added it to the get request for the google sheet in the latest version using the variable any_cors_url. I’ll see if this fixes things.

Sounds like you got it sorted out. For what it’s worth, CORS Anywhere’s demo instance is pretty heavily rate limited — so using that itself may cause your notebook to only load intermittently, as it rate-limits your proxy requests.

Great, thanks for the help. Do you know of any alternatives to cors-anywhere (other than asking people to allow CORS). For my purposes it seems to be working alright.

I don’t know of any good open alternatives. Asking people to fix their sites to allow CORS is the best … and failing that, running your own version of CORS-anywhere for your own purposes.

We’ve thought in the past about operating an Observable-hosted CORS proxy for notebooks to use to connect to public data endpoints that haven’t adopted CORS yet. I’ll take this issue as another positive vote for that old idea…