"module parse failed" error in gatsby-browser-entry.js

I'm new to gatsby and react. We're building a site for a small project using gatsby and decoupled drupal. I'm getting the following error, since I connected the frontend and backend, when I run 'gatsby develop'.

ERROR in ./node_modules/Gatsby/cache-dir/gatsby-browser-entry.js 22:4 Module parse failed: Unexpected token (22:4)

You may need an appropriate loader to handle this file type.
|
|   return (
>     <React.Fragment>
|       {finalData && render(finalData)}
|       {!finalData && <div>Loading (StaticQuery)</div>}
 @ ./src/pages/index.js 24:0-33 157:19-26
 @ ./.cache/sync-requires.js
 @ ./.cache/app.js
 @ multi ./node_modules/event-source-polyfill/src/eventsource.js (webpack)-hot-middleware/client.js?path=/__webpack_hmr&reload=true&overlay=false