Error during install of ng-bootstrap on my Angular 4 cli project

Hi angular community !

Yesterday I setup ng-bootstrap following these steps Getting started with Ng-Bootstrap and everyting worked fine. This morning I started my ng serve --open as usual and I got this message in the terminal:

ERROR in multi ./src/styles.css ./~/font-awesome/css/font-awesome.min.css ./~/bootstrap/dist/css/bootstrap.min.css
Module not found: Error: Can't resolve '/home/papamilo/Documents/Workspace/Test_a2json/front-end_copy_new/node_modules/bootstrap/dist/css/bootstrap.min.css' in '/home/papamilo/Documents/Workspace/Test_a2json/front-end_copy_new/node_modules/@angular/cli/models/webpack-configs'
 @ multi ./src/styles.css ./~/font-awesome/css/font-awesome.min.css ./~/bootstrap/dist/css/bootstrap.min.css
webpack: Failed to compile

`

NOTE: The thing very strange is when I go to my node module folder I cannot see any bootstrap folder

my angular-cli.json:

`{
  "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
  "project": {
  "name": "front-end"
  },
 "apps": [
{
  "root": "src",
  "outDir": "dist",
  "assets": [
    "assets",
    "favicon.ico"
  ],
  "index": "index.html",
  "main": "main.ts",
  "polyfills": "polyfills.ts",
  "test": "test.ts",
  "tsconfig": "tsconfig.app.json",
  "testTsconfig": "tsconfig.spec.json",
  "prefix": "app",
  "styles": [
    "styles.css",
    "../node_modules/font-awesome/css/font-awesome.min.css",
    "../node_modules/bootstrap/dist/css/bootstrap.min.css"
  ],
  "scripts": [
    "../node_modules/chart.js/dist/Chart.js",
    "./assets/js/jquery-3.1.1.min.js",
    "./responsive.js"
  ],
  "environmentSource": "environments/environment.ts",
  "environments": {
    "dev": "environments/environment.ts",
    "prod": "environments/environment.prod.ts"
    }
   }
  ],
   "e2e": {
   "protractor": {
    "config": "./protractor.conf.js"
  }
  },
  "lint": [
  {
  "project": "src/tsconfig.app.json"
  },
  {
  "project": "src/tsconfig.spec.json"
  },
  {
  "project": "e2e/tsconfig.e2e.json"
  }
  ],
"test": {
"karma": {
  "config": "./karma.conf.js"
   }
  },
  "defaults": {
"styleExt": "css",
"component": {}
  }
}

`

my package.json:

`{
"name": "front-end",
"version": "0.0.0",
"license": "Private",
"scripts": {
"ng": "ng",
"start": "ng serve",
"build": "ng build",
"test": "ng test",
"lint": "ng lint",
"e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
"@angular/animations": "^4.0.3",
"@angular/common": "^4.0.0",
"@angular/compiler": "^4.0.0",
"@angular/compiler-cli": "^4.1.0-rc.0",
"@angular/core": "^4.0.0",
"@angular/forms": "^4.0.0",
"@angular/http": "^4.0.0",
"@angular/platform-browser": "^4.0.0",
"@angular/platform-browser-dynamic": "^4.0.0",
"@angular/router": "^4.0.0",
"@ng-bootstrap/ng-bootstrap": "^1.0.0-alpha.30",
"@ngrx/store": "^4.0.0",
"@swimlane/ngx-charts": "^5.3.1",
"angular-highcharts": "^3.2.1",
"angular2-highcharts": "^0.5.5",
"chart.js": "^2.5.0",
"core-js": "^2.4.1",
"d3": "^4.9.1",
"font-awesome": "^4.7.0",
"highcharts": "^5.0.12",
"rxjs": "^5.1.0",
"typescript": "^2.2.1",
"zone.js": "^0.8.4"
  },
  "devDependencies": {
"@angular/cli": "^1.2.1",
"@angular/compiler-cli": "^4.0.0",
"@types/highcharts": "^4.2.56",
"@types/jasmine": "2.5.38",
"@types/node": "~6.0.60",
"canonical-path": "0.0.2",
"codelyzer": "~2.0.0",
"concurrently": "^3.2.0",
"jasmine-core": "~2.5.2",
"jasmine-spec-reporter": "~3.2.0",
"karma": "~1.4.1",
"karma-chrome-launcher": "~2.1.1",
"karma-cli": "~1.0.1",
"karma-coverage-istanbul-reporter": "^0.2.0",
"karma-jasmine": "~1.1.0",
"karma-jasmine-html-reporter": "^0.2.2",
"lodash": "^4.16.4",
"protractor": "~5.1.0",
"rimraf": "^2.5.4",
"ts-node": "~2.0.0",
"tslint": "~4.5.0",
"typescript": "~2.2.0"
  }
}`