Uncaught TypeError: Cannot convert undefined or null to object

[ptrhck]

When I start the development server, it seems that fetching the prismic data is going well:

Starting to fetch data from Prismic
               Fetch Prismic data: 504.140ms

However, If I visit the site the console logs:

dist.js:32 Uncaught TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at Object../node_modules/clean-tag/dist.js (dist.js:32)
    at __webpack_require__ (bootstrap:723)
    at fn (bootstrap:100)
    at Module../node_modules/grid-emotion/dist/index.es.js (index.es.js:1)
    at __webpack_require__ (bootstrap:723)
    at fn (bootstrap:100)
    at Module.<anonymous> (index.jsx:141)
    at Module../src/templates/post.jsx (post.jsx:135)
    at __webpack_require__ (bootstrap:723)
    at fn (bootstrap:100)
    at Object.<anonymous> (sync-requires.js:8)
    at Object../.cache/sync-requires.js (sync-requires.js:4)
    at __webpack_require__ (bootstrap:723)
    at fn (bootstrap:100)
    at Module../.cache/app.js (api-runner-browser.js:5)
    at __webpack_require__ (bootstrap:723)
    at fn (bootstrap:100)
    at Object.0 (randomNumber.js:1)
    at __webpack_require__ (bootstrap:723)
    at bootstrap:790
    at bootstrap:790

Any idea? What could I test?

[EugeneHerasymchuk]

Please extend your comment with code in your templates/post.jsx and gatsby-node

[ptrhck]

It was due to some package incompitability, going back to the provided package.json worked out.