UI5 extension project clone到WebIDE里后报找不到.project.json错误消息的处理

Suppose you try to create a new extension project based on one existing project:

This is caused by the fact that the necessary project json file is not created by standard development for My note application. All you need to do is to create a .project.json file manually and paste the following source code:

{

  "translation": {

    "translationDomain": "",

    "supportedLanguages": "en,fr,de",

    "defaultLanguage": "en",

    "defaultI18NPropertyFile": "i18n.properties",

    "resourceModelName": "i18n"

  }

}      

After that the button will be available again: