Could not find plugin "proposal-numeric-separator"

Create a fresh project of ionic with angular framework and cordova. Project created server successfully but when I am creating the build for android or ios it’s showing me an error, even in fresh project.

An unhandled exception occurred: [BABEL] /Users/apple/Desktop/sgni/www/3-es2015.js: Could not find plugin "proposal-numeric-separator". Ensure there is an entry in ./available-plugins.js for it. (While processing: "/Users/apple/Desktop/sgni/node_modules/@babel/preset-env/lib/index.js")
See "/private/var/folders/gx/h8s_w4k104x884fbdw8fsjq80000gn/T/ng-qDOkA1/angular-errors.log" for further details.
[ERROR] An error occurred while running subprocess ng.

IONIC Version: 6.3.0
NPM: 6.14.1
Angular CLI: 9.0.4
OS: MAC
Node: v10.16.2
Cordova: 9.0.0

but its strange thing when I replaced node_modules from my old project it works perfectly and creating a build successfully.

Can anyone tell me, is there any way to solve this issue?

3 Likes

I got the same error while creating blank or tabs projects. Following is my Ionic info:
Ionic:
Ionic CLI : 6.3.0
Utility:
cordova-res : 0.10.0
native-run : 0.3.0
System:
NodeJS : v12.14.0
npm : 6.13.4
OS : Windows 10

package.json:
{
“name”: “trial_1”,
“version”: “0.0.1”,
“author”: “Ionic Framework”,
“homepage”: “https://ionicframework.com/”,
“scripts”: {
“ng”: “ng”,
“start”: “ng serve”,
“build”: “ng build”,
“test”: “ng test”,
“lint”: “ng lint”,
“e2e”: “ng e2e”
},
“private”: true,
“dependencies”: {
@angular/common”: “~8.2.14”,
@angular/core”: “~8.2.14”,
@angular/forms”: “~8.2.14”,
@angular/platform-browser”: “~8.2.14”,
@angular/platform-browser-dynamic”: “~8.2.14”,
@angular/router”: “~8.2.14”,
@ionic-native/core”: “^5.0.0”,
@ionic-native/splash-screen”: “^5.0.0”,
@ionic-native/status-bar”: “^5.0.0”,
@ionic/angular”: “^5.0.0”,
“cordova-android”: “^8.1.0”,
“core-js”: “^2.5.4”,
“rxjs”: “~6.5.1”,
“tslib”: “^1.9.0”,
“zone.js”: “~0.9.1”
},
“devDependencies”: {
@angular-devkit/build-angular”: “~0.803.20”,
@angular/cli”: “~8.3.23”,
@angular/compiler”: “~8.2.14”,
@angular/compiler-cli”: “~8.2.14”,
@angular/language-service”: “~8.2.14”,
@ionic/angular-toolkit”: “^2.1.1”,
@types/jasmine”: “~3.3.8”,
@types/jasminewd2”: “~2.0.3”,
@types/node”: “~8.9.4”,
“codelyzer”: “^5.0.0”,
“cordova-plugin-device”: “^2.0.2”,
“cordova-plugin-ionic-keyboard”: “^2.2.0”,
“cordova-plugin-ionic-webview”: “^4.1.3”,
“cordova-plugin-splashscreen”: “^5.0.2”,
“cordova-plugin-statusbar”: “^2.4.2”,
“cordova-plugin-whitelist”: “^1.3.3”,
“jasmine-core”: “~3.4.0”,
“jasmine-spec-reporter”: “~4.2.1”,
“karma”: “~4.1.0”,
“karma-chrome-launcher”: “~2.2.0”,
“karma-coverage-istanbul-reporter”: “~2.0.1”,
“karma-jasmine”: “~2.0.1”,
“karma-jasmine-html-reporter”: “^1.4.0”,
“protractor”: “~5.4.0”,
“ts-node”: “~7.0.0”,
“tslint”: “~5.15.0”,
“typescript”: “~3.4.3”
},
“description”: “An Ionic project”,
“cordova”: {
“plugins”: {
“cordova-plugin-whitelist”: {},
“cordova-plugin-statusbar”: {},
“cordova-plugin-device”: {},
“cordova-plugin-splashscreen”: {},
“cordova-plugin-ionic-webview”: {
“ANDROID_SUPPORT_ANNOTATIONS_VERSION”: “27.+”
},
“cordova-plugin-ionic-keyboard”: {}
},
“platforms”: [
“android”
]
}
}

Forgot to mention. Ionic serve is working fine; however, ionic cordova run android --prod failed with the captioned error. Aleady tried without prod flag…no luck!

Error message:
An unhandled exception occurred: [BABEL] E:\Ionic 4\errortest\www\common-es2015.62b80ffaba280638c0d3.js: Could not find plugin “proposal-numeric-separator”. Ensure there is an entry in ./available-plugins.js for it. (While processing: “E:\Ionic 4\errortest\node_modules\@babel\preset-env\lib\index.js”)
See “C:\Users\root\AppData\Local\Temp\ng-SWzRW2\angular-errors.log” for further details.
[ERROR] An error occurred while running subprocess ng.

It has been answered few hours ago, I’ll leave you here the link for the temporary workaround:

1 Like

I have the same problem

  1. delete node_modules and package-lock.json
  2. add "resolutions": { "@babel/preset-env": "^7.8.7" } to package.json
  3. npm install npm-force-resolutions --save-dev
  4. npm install
  5. npx npm-force-resolutions
  6. npm install again
  7. ionic build
18 Likes

Yes, it works for me Thanks

its amazing, work fine thanks

from

An unhandled exception occurred: [BABEL] E:\Worker Application\Project\find_workers\www\0-es2015.js: Could not find plugin “proposal-numeric-separator”. Ensure there is an entry in ./available-plugins.js for it. (While processing: “E:\Worker Application\Project\find_workers\node_modules\@babel\preset-env\lib\index.js”)
See “C:\Users\ALEEMU~1\AppData\Local\Temp\ng-DsB5yM\angular-errors.log” for further details.
[ERROR] An error occurred while running subprocess ng.

This works indeed, but not when I try to build a production version using the command ‘ionic build --prod’.

thanks! it’s working for me

I followed the steps but same errors:
n unhandled exception occurred: [BABEL] E:\custompipes\www\1-es2015.js: Could not find plugin “proposal-numeric-separator”. Ensure there is an entry in ./available-plugins.js for it. (While processing: “E:\custompipes\node_modules\@babel\preset-env\lib\index.js”)
See “C:\AppData\Local\Temp\ng-uVUfNq\angular-errors.log” for further details.
[ERROR] An error occurred while running subprocess ng.

Ionic serve is working but not with ionic cordova run android (–prod) ionic build also failed. It’s been two days now…please help…

It worked for me. Thank bro so much

Thanx man It works. Any idea how this error originated since it wasn’t there a week ago?

Thanks! This solution saved my day! But I am not sure why this problem exist and why this solution works. Anyone has idea?

is
node_modules And package-lock.json directly delete folder from project.

I had this issue, some of the fixes here worked for me until I had to do ionic build --prod. The issue reappeared then.

What worked for me was to use npm to downgrade the @angular-devkit/build-angular from 803.25 to 803.23.

Hopefully they will fix the library in future versions. Seems to be a recent issue

open package.json

"dependencies": {
    "@babel/compat-data": "7.8.0"
}

run command npm install and then build your project and it should work.

2 Likes