graphql-schema-from-json: Error with showing results

I used the code in the example & ran ‘npm start’

"start": "babel-node index.js --presets es2015,stage-2"

Now using node v8.9.0 (npm v5.5.1)
me@me-Latitude-E7470:~/Development/Projects/g$ npm start
> g@1.0.0 start /home/me/Development/Projects/g
> babel-node index.js --presets es2015,stage-2

/home/me/Development/Projects/g/node_modules/graphql/jsutils/invariant.js:18
    throw new Error(message);
    ^

Error
    at invariant (/home/me/Development/Projects/g/node_modules/graphql/jsutils/invariant.js:18:11)
    at printType (/home/me/Development/Projects/g/node_modules/graphql/utilities/schemaPrinter.js:151:83)
    at Array.map (<anonymous>)
    at printFilteredSchema (/home/me/Development/Projects/g/node_modules/graphql/utilities/schemaPrinter.js:80:87)
    at printSchema (/home/me/Development/Projects/g/node_modules/graphql/utilities/schemaPrinter.js:44:10)
    at Object.<anonymous> (/home/me/Development/Projects/g/index.js:26:13)
    at Module._compile (module.js:635:30)
    at loader (/home/me/Development/Projects/g/node_modules/babel-register/lib/node.js:144:5)
    at Object.require.extensions.(anonymous function) [as .js] (/home/me/Development/Projects/g/node_modules/babel-register/lib/node.js:154:7)
    at Module.load (module.js:554:32)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! g@1.0.0 start: `babel-node index.js --presets es2015,stage-2`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the g@1.0.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/me/.npm/_logs/2017-11-03T12_10_43_198Z-debug.log