Sass-loader要求node-sass> = 4（即使存在）

我执行了对angular 6的更新。在ng serve -o期间，我收到sass-loader期望node-sass的错误。运行ng serve -o之后，我收到：

ERROR in ./src/sass/styles.scss (./node_modules/raw-loader!./node_modules/postcss-loader/lib??embedded!./node_modules/sass-loader/lib/loader.js??ref--14-3!./src/sass/styles.scss)
    Module build failed: Error: `sass-loader` requires `node-sass` >=4. Please install a compatible version.
    at Object.sassLoader (node_modules\sass-loader\lib\loader.js:31:19)
ERROR in ./src/app/app.component.scss
Module build failed: Error: `sass-loader` requires `node-sass` >=4. Please install a compatible version.
    at Object.sassLoader (node_modules\sass-loader\lib\loader.js:31:19)
ERROR in x.component.scss
Module build failed: Error: `sass-loader` requires `node-sass` >=4. Please install a compatible version.
    at Object.sassLoader (\node_modules\sass-loader\lib\loader.js:31:19)
ERROR in x.component.scss
Module build failed: Error: `sass-loader` requires `node-sass` >=4. Please install a compatible version.
    at Object.sassLoader (loader.js:31:19)
ERROR in .x.component.scss
Module build failed: Error: `sass-loader` requires `node-sass` >=4. Please install a compatible version.
    at Object.sassLoader (node_modules\sass-loader\lib\loader.js:31:19)

显然，我检查了所有内容（我认为），但不知道发生了什么。

Package.Json：

"devDependencies": {
"@angular-devkit/build-angular": "~0.6.0",
"@angular/cli": "6.0.0",
"@angular/compiler-cli": "6.0.0",
"@angular/language-service": "6.0.0",
"@types/jasmine": "~2.8.3",
"@types/jasminewd2": "~2.0.2",
"@types/node": "~6.0.106",
"codelyzer": "^4.0.1",
"jasmine-core": "~2.8.0",
"jasmine-spec-reporter": "~4.2.1",
"karma": "~2.0.0",
"karma-chrome-launcher": "~2.2.0",
"karma-html-detailed-reporter": "^1.1.21",
"karma-jasmine": "~1.1.0",
"karma-jasmine-html-reporter": "^0.2.2",
"karma-phantomjs-launcher": "^1.0.4",
"karma-teamcity-reporter": "^1.1.0",
"phantomjs-prebuilt": "^2.1.16",
"protractor": "~5.1.2",
"node-sass": "^4.9.0",
"sass-loader": "^7.0.1",
"ts-node": "~4.1.0",
"tslint": "~5.9.1",
"typescript": "2.7.2"
}

dir -l node_modules说：

...
05/07/2018  08:53 AM    <DIR>          node-sass
...
05/07/2018  08:53 AM    <DIR>          sass-loader
...

我执行了：

npm rebuild node-sass 

第二方法：我删除了本地节点模块以及％User％\ AppData \ Roaming \ npm-cache。然后我删除了锁定文件并执行了npm

npm cache clear --force
npm install

但是仍然没有成功。

我想念什么？