You appear to be offline. Falling back to the local Yarn cache.

[8483]

sudo npm i -g create-react-app
create-react-app app

Keeps giving this error no matter what I do.

Installing packages. This might take a couple of minutes.
Installing react, react-dom, and react-scripts...

You appear to be offline.
Falling back to the local Yarn cache.

yarn add v1.3.2
info No lockfile found.
[1/4] Resolving packages...
error Couldn't find any versions for "react" that matches "latest" in our cache (possible versions are ""). This is usually caused by a missing entry in the lockfile, running Yarn without the --offline flag may help fix this issue.
info Visit https://yarnpkg.com/en/docs/cli/add for documentation about this command.

I am indeed online.

[8483]

Solution: yarnpkg/yarn#3227

npm config set registry "https://registry.npmjs.org"