Problem working with an imported project in ionic 3 ( failed to load index.html )

My friend shared me a project she had worked in the last 4 months. It was uploaded in git-lab. I cloned the project and then downloaded and installed exactly like her ionic, cordova, nodejs and npm version. Now it shows the problem that failed to load index.html and the web page say try later.

this what the command line shows

C:\Users\user\Documents\VA2>ionic serve
> ionic-app-scripts serve --address --port 8100 --livereload-port 35729 --dev-logger-port 53703 --nobrowser
[app-scripts] [16:00:46]  ionic-app-scripts 3.1.10
[app-scripts] [16:00:46]  watch started ...
[app-scripts] [16:00:46]  build dev started ...

[INFO] Development server running!

      Local: http://localhost:8100
      DevApp: vox@8100 on DESKTOP-6108QN7

      Use Ctrl+C to quit this process

[INFO] Browser window opened to http://localhost:8100!

[app-scripts] [16:00:46]  Proxy added:/api => http://***.********.***/api
[app-scripts] (node:20584) UnhandledPromiseRejectionWarning: Error: A watch configured to watch the following paths failed to start. It likely that a file referenced does not exist: C:\Users\user\Documents\VA2\src\assets\**\*, C:\Users\user\Documents\VA2\src\index.html, C:\Users\user\Documents\VA2\src\manifest.json, C:\Users\user\Documents\VA2\src\service-worker.js, C:\Users\user\Documents\VA2\node_modules\ionicons\dist\fonts\**\*, C:\Users\user\Documents\VA2\node_modules\ionic-angular\fonts\**\*, C:\Users\user\Documents\VA2\node_modules\ionic-angular\polyfills\polyfills.js, C:\Users\user\Documents\VA2\node_modules\sw-toolbox\sw-toolbox.js
[app-scripts]     at new BuildError (C:\Users\user\Documents\VA2\node_modules\@ionic\app-scripts\dist\util\errors.js:16:28)
[app-scripts]     at Timeout._onTimeout (C:\Users\user\Documents\VA2\node_modules\@ionic\app-scripts\dist\watch.js:71:20)
[app-scripts]     at ontimeout (timers.js:498:11)
[app-scripts]     at tryOnTimeout (timers.js:323:5)
[app-scripts]     at Timer.listOnTimeout (timers.js:290:5)
[app-scripts] (node:20584) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
[app-scripts] (node:20584) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
[app-scripts] [16:00:53]  Failed to load index.html

and then what ionic info shows


  ionic (Ionic CLI)  : 4.1.2 (C:\Users\user\AppData\Roaming\npm\node_modules\ionic)
  Ionic Framework    : ionic-angular 3.9.2
  @ionic/app-scripts : 3.1.10


  cordova (Cordova CLI) : 8.0.0
  Cordova Platforms     : android 7.0.0
  Cordova Plugins       : not available


  NodeJS : v8.11.2 (C:\Program Files\nodejs\node.exe)
  npm    : 6.4.1
  OS     : Windows 10

what to do ?

I had a similar problem, I searched for stackoerlow answers, and on forums, but I couldn’t fix it. I then installed yarn using the command yarn install and then ran the app ionic again and ran successfully. However, I am not sure if it is due to the lack of libraries of yarn, but after I successfully ran the yarn install command, I would like to comment.