Angular 8 to Angular 9 migration issues

Question

I have migrated from angular 8 to angular 9 then i got the below issues For this i have removed the node_modules many times and installed freshly but still i am getting the below issues:

An unhandled exception occurred: Cannot find module 'webpack/lib/ParserHelpers'
Require stack:
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\worker-plugin\dist\worker-plugin.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular-devkit\build-angular\src\angular-cli-files\models\webpack-configs\worker.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular-devkit\build-angular\src\angular-cli-files\models\webpack-configs\index.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular-devkit\build-angular\src\browser\index.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular-devkit\build-angular\src\dev-server\index.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular\cli\node_modules\@angular-devkit\architect\node\node-modules-architect-host.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular\cli\node_modules\@angular-devkit\architect\node\index.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular\cli\models\architect-command.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular\cli\commands\serve-impl.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular-devkit\schematics\tools\export-ref.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular-devkit\schematics\tools\index.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular\cli\utilities\json-schema.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular\cli\models\command-runner.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular\cli\lib\cli\index.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular\cli\lib\init.js
- E:\ng9\Fxt\Web\src\main\ui\material\node_modules\@angular\cli\bin\ng
See "C:\Users\ADMIN\AppData\Local\Temp\ng-MOOMPS\angular-errors.log" for further details.
npm ERR! code ELIFECYCLE
npm ERR! syscall spawn
npm ERR! file C:\WINDOWS\system32\cmd.exe
npm ERR! errno ENOENT
npm ERR! material@3.0.0 start: `ng serve --proxy-config proxy.config.json`
npm ERR! spawn ENOENT
npm ERR!
npm ERR! Failed at the material@3.0.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\ADMIN\AppData\Roaming\npm-cache\_logs\2020-11-17T16_17_33_897Z-debug.log

Answer 1

uninstall webpack and then again install it globally.

npm uninstall -g webpack

npm install webpack -g

uninstall cli and then again install it globally.

npm uninstall -g @angular/cli

npm install -g @angular/cli

And now try to install node modules again.

rm node_modules -r -force

rm package-lock.json

npm cache verify

npm install