I have a problem when I try to run ng serve on a recently created Angular project.
The version I'm using is 9.1.4, this error does not occur on a project with an older Angular version.
Package Version
-----------------------------------------------------------
@angular-devkit/architect 0.901.4
@angular-devkit/build-angular 0.901.4
@angular-devkit/build-optimizer 0.901.4
@angular-devkit/build-webpack 0.901.4
@angular-devkit/core 9.1.4
@angular-devkit/schematics 9.1.4
@angular/cli 9.1.4
@ngtools/webpack 9.1.4
@schematics/angular 9.1.4
@schematics/update 0.901.4
rxjs 6.5.5
typescript 3.8.3
webpack 4.42.0
After executing ng serve or ng build:
chunk {main} main.js, main.js.map (main) 2 kB [initial] [rendered]<br>
chunk {polyfills} polyfills.js, polyfills.js.map (polyfills) 679 bytes [initial] [rendered]<br>
chunk {runtime} runtime.js, runtime.js.map (runtime) 6.15 kB [entry] [rendered]<br>
chunk {styles} styles.js, styles.js.map (styles) 12.4 kB [initial] [rendered]<br>
chunk {vendor} vendor.js, vendor.js.map (vendor) 339 kB [initial] [rendered]<br>
Date: 2020-05-08T02:06:46.145Z - Hash: 1a1b937f0ca2bb37634b - Time: 4087ms<br>
**ERROR in TypeError: Cannot read property 'flags' of undefined**
at resolveAlias (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:36513:37)
at checkAliasSymbol (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:64502:26)
at checkImportBinding (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:64534:13)
at checkImportDeclaration (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:64552:29)
at checkSourceElementWorker (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:64961:28)
at checkSourceElement (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:64800:17)
at Object.forEach (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:317:30)
at checkSourceFileWorker (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:65123:20)
at checkSourceFile (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:65091:13)
at getDiagnosticsWorker (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:65179:17)
at Object.getDiagnostics (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:65165:24)
at C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:98703:85
at runWithCancellationToken (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:98665:24)
at getBindAndCheckDiagnosticsForFileNoCache (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:98691:20)
at getAndCacheDiagnostics (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:98956:26)
at getBindAndCheckDiagnosticsForFile (C:\Cursos\Angular\ang-hello-world\node_modules\typescript\lib\typescript.js:98688:20)
** **Angular Live Development Server is listening on localhost:4200, open your browser on http://localhost:4200/** **
The result I get on my browser after running this project is:
Cannot GET /
try this solution :
npm install @angular/core@9.1.4 @angular/animations@9.1.4 @angular/common@9.1.4 @angular/forms@9.1.4 @angular/platform-browser@9.1.4 @angular/router@9.1.4 @angular/platform-browser-dynamic@9.1.4 @angular/compiler@9.1.4 @angular/compiler-cli@9.1.4 @angular/language-service@9.1.4
npm install
ng serve
edit
If you use angular 9.1.6 it should be fine now
npm update @angular/cli @angular/core
original post
Something is broken in Angular 9.1.5 - if you run the following it should work:
npm install @angular/core@9.1.4 @angular/animations@9.1.4 @angular/common@9.1.4 @angular/forms@9.1.4 @angular/platform-browser@9.1.4 @angular/router@9.1.4 @angular/platform-browser-dynamic@9.1.4 @angular/compiler@9.1.4 @angular/compiler-cli@9.1.4 @angular/language-service@9.1.4
ng build
Just spent about 4-5 hours trying to fix it myself...
The issue seems to stem from using Angular CLI 9.1.4 with Angular 9.1.5 (most likely the compiler
You'll see the issue when you do
ng --version
if you get:
Angular CLI: 9.1.4
Node: 12.16.3
OS: win32 x64
Angular: 9.1.5
... animations, cli, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router
Ivy Workspace: Yes
Then you will need to follow the npm installs i listed above
@Matt's answer worked for me as well for ng serve, but needed additional steps. First do these steps "Quoting the steps from his answer":
ng --version. Go to next step if you get:Angular CLI: 9.1.4
Node: 12.16.3
OS: win32 x64
Angular: 9.1.5
... animations, cli, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router
Ivy Workspace: Yes
npm install @angular/core@9.1.4 @angular/animations@9.1.4 @angular/common@9.1.4 @angular/forms@9.1.4 @angular/platform-browser@9.1.4 @angular/router@9.1.4 @angular/platform-browser-dynamic@9.1.4 @angular/compiler@9.1.4 @angular/compiler-cli@9.1.4 @angular/language-service@9.1.4
Couple of more steps for more ng serve to finally work.
An unhandled exception occurred: Cannot find module 'tslib'
For this I installed the tslib package manually using npm.You seem to not be depending on "@angular/core" and/or "rxjs". This is an error.. For this I referred "You seem to not be depending on "@angular/core"." and voila! ng serve worked!9.1.6 just released, should fix that issue
Got the same problem updating from 10.1.0 to 11.1.1.
Updating TypeScript to the latest Version from 4.0.2 to 4.1.3 solved the problem:
npm i typescript@latest