foundation-sites: Can't run npm start anymore.

When I run npm start I get:

[10:54:15] Using gulpfile ~/Local Sites/mqv/app/public/wp-content/themes/mqv/gulpfile.js [10:54:15] Starting ‘default’… [10:54:15] Starting ‘build’… [10:54:15] Starting ‘clean’… [10:54:15] Finished ‘clean’ after 4.46 ms [10:54:15] Starting ‘styles’… [10:54:15] Starting ‘scripts’… [10:54:15] Starting ‘images’… [10:54:15] Starting ‘copy’… [10:54:15] ‘styles’ errored after 52 ms [10:54:15] TypeError: plugin.sass is not a function at styles (/Users/deryck/Local Sites/mqv/app/public/wp-content/themes/mqv/gulpfile.js:115:22) at bound (domain.js:396:14) at runBound (domain.js:409:12) at asyncRunner (/Users/deryck/Local Sites/mqv/app/public/wp-content/themes/mqv/node_modules/async-done/index.js:55:18) at process._tickCallback (internal/process/next_tick.js:61:11) [10:54:15] ‘build’ errored after 58 ms [10:54:15] ‘default’ errored after 61 ms [10:54:15] The following tasks did not complete: scripts, images, copy [10:54:15] Did you forget to signal async completion? npm ERR! code ELIFECYCLE npm ERR! errno 1 npm ERR! foundation-zurb-template@1.0.0 start: gulp npm ERR! Exit status 1 npm ERR! npm ERR! Failed at the foundation-zurb-template@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! /Users/deryck/.npm/_logs/2019-03-18T13_54_15_911Z-debug.log

I tried to install gulp-sass without success. Delete node_modules and use npm install. The install was fine, however, npm start keeps giving error. Start happens suddenly. I did not update anything.

Gulpfile function:

var gulp = require('gulp'),
    gutil = require('gulp-util'),
    browserSync = require('browser-sync').create(),
    filter = require('gulp-filter'),
    rimraf = require('rimraf'),
    plugin = require('gulp-load-plugins')();

// Compile Sass, Autoprefix and minify
function styles() {
    return gulp.src(SOURCE.styles)
        .pipe(plugin.plumber(function (error) {
            gutil.log(gutil.colors.red(error.message));
            this.emit('end');
        }))
        .pipe(plugin.sourcemaps.init())
        .pipe(plugin.sass({
            includePaths: ["node_modules/foundation-sites/scss", "node_modules/motion-ui/src"]
        }))
        .pipe(plugin.autoprefixer({
            browsers: [
                'last 2 versions',
                'ie >= 9',
                'ios >= 7'
            ],
            cascade: false
        }))
        .pipe(plugin.cssnano())
        .pipe(plugin.sourcemaps.write('.'))
        .pipe(gulp.dest(ASSETS.styles))
        .pipe(browserSync.stream())
}

package.json

{
  "name": "foundation-zurb-template",
  "version": "1.0.0",
  "description": "Official ZURB Template for Foundation for Sites.",
  "main": "gulpfile.js",
  "scripts": {
    "start": "gulp",
    "build": "gulp build --production"
  },
  "author": "ZURB <foundation@zurb.com>",
  "license": "MIT",
  "devDependencies": {
    "babel-preset-es2015": "^6.5.0",
    "browser-sync": "^2.11.0",
    "foundation-sites": "6.4.3",
    "gulp": "^4.0.0",
    "gulp-autoprefixer": "^2.3.1",
    "gulp-babel": "^6.1.2",
    "gulp-concat": "^2.5.2",
    "gulp-cssnano": "^2.1.1",
    "gulp-filter": "^5.0.0",
    "gulp-imagemin": "^3.1.1",
    "gulp-jshint": "^1.11.0",
    "gulp-load-plugins": "^1.4.0",
    "gulp-newer": "^1.3.0",
    "gulp-plumber": "^1.0.1",
    "gulp-sourcemaps": "^1.6.0",
    "gulp-uglify": "^1.2.0",
    "gulp-util": "^3.0.8",
    "gulp-wp-pot": "^2.0.4",
    "jshint-stylish": "^2.0.0",
    "motion-ui": "^1.2.2",
    "rimraf": "^2.4.3",
    "what-input": "^4.1.3"
  },
  "repository": {
    "type": "git",
    "url": "https://github.com/zurb/foundation-zurb-template.git"
  },
  "bugs": {
    "url": "https://github.com/zurb/foundation-sites/issues",
    "email": "foundation@zurb.com"
  },
  "babel": {
    "presets": [
      "es2015"
    ]
  },
  "private": true,
  "dependencies": {}
}