我遇到了同样的问题，并且对我有用:

I had the same issue and this worked for me:

1. 删除这些文件/文件夹(从Angular根文件夹中):
   

1. Delete these files/ folders (from your Angular root folder):
   

• package-lock.json(不是 package.json)
• /node_modules文件夹
• /dist文件夹

• package-lock.json (Not the package.json)
• /node_modules folder
• /dist folder

执行命令(重新生成package-lock.json和/node_modules):

Execute command (regenerate the package-lock.json and the /node_modules):

• $npm install
  

现在一切正常，是package-lock.json导致npm下载旧版本的依赖项.

Everything should work now, it was the package-lock.json that caused npm to download old versions of dependencies.