Error in running "sanity start" command, package 'next' not found in schema.js file.

sanity start

✔ Checking configuration files...
⠦ Compiling...webpack built 13b315e7094243c5af96 in 10658ms
✔ Compiling...
Failed to compile.

Error in ./schemas/schema.js (part:@sanity/base/schema)
Module build failed: Error [ERR_MODULE_NOT_FOUND]: Cannot find package 'next' imported from /home/user/Documents/dci/my-projects/myPortfolio/portfolio-sanity/babel-virtual-resolve-base.js
    at Generator.next (<anonymous>)
    at new Promise (<anonymous>)
 @ ./node_modules/@sanity/default-layout/lib/schemaErrors/SchemaErrorReporter.js 8:37-72
 @ ./node_modules/@sanity/default-layout/lib/defaultLayout/DefaultLayout.js
 @ ./node_modules/@sanity/default-layout/lib/defaultLayout/index.js
 @ ./node_modules/@sanity/default-layout/lib/Root.js (part:@sanity/base/root)
 @ ./node_modules/@sanity/base/lib/components/SanityRoot.js (part:@sanity/base/sanity-root)
 @ ./node_modules/@sanity/server/lib/browser/entry-dev.js
 @ multi ./node_modules/@sanity/server/lib/browser/entry-dev.js

import createSchema from 'part:@sanity/base/schema-creator'
import schemaTypes from 'all:part:@sanity/base/schema-type'
import home from './home'
import about from './about'
import project from './project'

export default createSchema({
  name: 'default',
  types: schemaTypes.concat([
    home,
    about,
    project,
  ]),
})