For a bug with Next.js 12 and @graphql-tool/load-files v6.4.0+
When @graphql-tools/load-files is set to version 6.3.2, it works.
When @graphql-tools/load-files is set to version 6.4.0 or above, it fails.
When changing branches don't forget to remove lock file, node_modules and cache.
rm -rf package-lock.json node_modules/ .next && npm i
npm i
npm run dev
JSON output of schema should be visible at http://localhost:3000/api/graphql