While attempting to create a new ReactJS app with the create-react-app tool, I encountered the following error: "error 400 Bad Request: run-async@^2.2.0". See the screenshot below.
After some research, I found the node npm cache could be corrupted. So running the following command fixed the issue for me.
$ npm cache verify
The create-react-app tool now can complete successfully, as shown below: $ npx create-react-app myapp