Vue 3 The template root requires exactly one element.eslint-plugin-vue

I ended up turning off Vetur linting. Vetur thinks that it is a Vue 2 project becuase it is in a VS Code workspace.

https://github.com/vuejs/vetur/issues/2299#issuecomment-696015374

You can solve this by doing

F1>Preferences:Open Settings (JSON)

paste

"vetur.validation.template": false,
"vetur.validation.script": false,
"vetur.validation.style": false,

The error occurred with me, because I had not opened the project root in VS Code, but the parent folder, and Vetur thus looked in this for the package.json.