Error while saving content type

System Information
  • Strapi Version: 3.6.8
  • Operating System: MacOS
  • Database: sqlite3
  • Node Version: 14.16.1
  • NPM Version: 6.14.12
  • Yarn Version: -

I’m using a fresh installation of strapi. No files changes, no content added.
I run it in development mode locally using “npm run develop”.
I created my account and i created a new content type named “author”.
The content type page shows “An error occurred” and an infinite spinner and i get some errors in console:

INJECT_ERROR TypeError: Cannot convert undefined or null to object
at Function.keys ()
at Object.t.getHeaders (inject.js:1)
at inject.js:1
at c (inject.js:1)
at inject.js:1

After refreshing the page, the model is successfully created, but every time i hit save in content-type page, i get those errors and an infinite spinner.