Could not find plugin "proposal-class-properties". Ensure there is an entry in ./available-plugins.js

[nagthgr8]

Bug Report

Current behavior
The ng build in Angular 8 & 9 produces below error
[BABEL] C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\dist\main-es2015.js: Could not find plugin "proposal-class-properties". Ensure there is an entry in ./available-plugins.js for it. (While processing: "C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules\@babel\preset-env\lib\index.js")
Error: [BABEL] C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\dist\main-es2015.js: Could not find plugin "proposal-class-properties". Ensure there is an entry in ./available-plugins.js for it. (While processing: "C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules\@babel\preset-env\lib\index.js")
at getPlugin (C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules@babel\preset-env\lib\index.js:67:11)
at C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules@babel\preset-env\lib\index.js:258:62
at Array.map ()
at C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules@babel\preset-env\lib\index.js:258:43
at C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules@babel\helper-plugin-utils\lib\index.js:19:12
at C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules@babel\core\lib\config\full.js:179:14
at Generator.next ()
at Function. (C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules@babel\core\lib\gensync-utils\async.js:26:3)
at Generator.next ()
at step (C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules\gensync\index.js:254:32)
at evaluateAsync (C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules\gensync\index.js:284:5)
at Function.errback (C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules\gensync\index.js:108:7)
at errback (C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules@babel\core\lib\gensync-utils\async.js:70:18)
at async (C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules\gensync\index.js:183:31)
at onFirstPause (C:\Users\NagaRam\source\repos\MyyPub.Web\ClientApp\node_modules\gensync\index.js:209:13)
at Generator.next ()

Expected behavior
The build should be complete without errors

Environment
npx: installed 1 in 5.113s

System:
OS: Windows 10 10.0.17134
Binaries:
Node: 12.16.3 - C:\Program Files\nodejs\node.EXE
npm: 6.14.4 - C:\Program Files\nodejs\npm.CMD
npmPackages:
@babel/plugin-proposal-class-properties: ^7.12.1 => 7.12.1

• Babel version(s): ^7.12.1 => 7.12.1
• Node/npm version: Node 12/npm 6
• OS: [e.g. Windows 10
• Monorepo: no
• How you are using Babel: CLI

Possible Solution

Additional context

[babel-bot]

Hey @nagthgr8! We really appreciate you taking the time to report an issue. The collaborators on this project attempt to help as many people as possible, but we're a limited number of volunteers, so it's possible this won't be addressed swiftly.

If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack community that typically always has someone willing to help. You can sign-up here for an invite."

[nagthgr8]

This is a straight bug & a blocker should have fixed by now instead of workarounds, the following steps fixed the issue but there should be a much efficient way
add "resolutions": { "@babel/preset-env": "7.5.5" }, in package.json。

run npx npm-force-resolutions

run npm install or yarn
ref: https://stackoverflow.com/questions/62585989/could-not-find-plugin-proposal-class-properties-how-to-resolve-this

[nicolo-ribaudo]

This has been fixed in @babel/preset-env@7.8.7 - #11201

[nagthgr8]

The issue is actually resolved by adding npm i @babel/compat-data@7.8.0

[FelipeBeleno]

El problema se resuelve realmente agregando npm i @ babel / compat-data @ 7.8.0

Funciono eres un crack bro.