WebGL publisher (build is corrupted or missing)

In this tutorial I see that Window>Share WebGL Game is not available. Instead I have Publish>WebGL Project.

But if I try to select a working WebGL build I get this error:

Do I need to zip my build folder first or something?

Hello @AllTheGoodNamesWereTaken I had the same problem and was wondering if you had figured it out.

Hello! Same too.
I try zip the folder and publish it through Unity Play.
Still don’t understand how to manipulate on Unity Editor.

I don’t think this is the same problem, but at least this one is reported.