Solution for your Errors and Exceptions

Error -  npm ERR ! Unable to authenticate , need : Bearer authorization_uri = https : //login.windows.net/*********, Basic realm="https://pkgsprodcus1.pkgs.visualstudio.com/", TFS-Federated Root Cause - When you have configured your package registry in .npmrc file as below. registry =https://<your-organization-cloud>.pkgs.visualstudio.com/_packaging/bdcNpmFeed/npm/registry/ And your credentials are not updated or has expired then you can face the authentication issue. Solution - run below command in visual studio code to get authenticated. vsts - npm - auth - config . npmrc Thanks

Error -  Unexpected token T in JSON at position 0  Root Cause - When upgrading to Angular CLI 6 and then you run build or install command then you can face this error. Solution - Make sure correct version of Angular CLI is installed. For me Angular CLI 6 did not work so finally I upgraded directly to Angular 7 instead of Angular 6 first as per angular upgrade guide . Thanks

Error -  The serve command requires to be run in an Angular project, but a project definition could not be found Root Cause - When there is no project definition file in your project then you will see this error when you will run ng-serve or ng-build commands. Project definition file - In Angular project definition file is generated when you create new application or upgrade existing application. In Angular versions lesser than 6 this file name is .angulat-cli.json  and in Angular version 6 and above it's name is angular.json . Solution -   So while running the angular build or run commands make sure you have correct project definition file. If you are upgrading your application from Angular 5 or lesser versions to Angular 6 and greater versions then you need to run below command to generate new project definition and other related files. ng update @angular/cli   // run it twice, If it's not generating then again try to run below commands in same sequence....

Warning -  Your global Angular CLI version (8.3.3) is greater than your local version (1.6.5). The local Angular CLI version is used. Explanation - When you run an angular application and you have different versions of Angular CLI installed globally and in local project then you can see this warning or error. Solution - There are 3 things here. Either you can continue with this warning You can install matching version of angular CLI to global in local project by using below command.           npm install @angular/cli@version         3. Install Latest version of Angular CLI globally and in project as well.          To install latest angular CLI globally use below command.           npm install -g @angular/cli          To install latest angular CLI in project use below command.           npm install @angular/cli Thanks

Error -  Cannot find module 'rxjs-compat'. Complete error look like this. ERROR in node_modules/rxjs/Rx.d.ts(1,15): error TS2307: Cannot find module 'rxjs-compat' Root Cause - When you update your angular application from Angular 2/4/5 to Greater versions of Angular then some times you face this error. Angular CLI does not add 'rxjs-compat' package automatically or some issue in the package. Solution - To get rid of this error install this package in the application. npm install rxjs-compat Thanks

Error -  Property 'map' does not exist on type 'Observable<Response>' Root Cause - When you upgrade your application from Angular 2/4/5 to Angular 6/7/8/9  then there are some functions that can not support in major versions.  Solution - To get rid of this error change your import statements as below. import  { Observable }  from   'rxjs' ; import  { catchError, map }  from   'rxjs/operators' ; And change your implementation for map function as below using ' Pipe ' function. delete(url: string, options?: any): Observable<any> {          return   this ._http.delete( ` ${ this ._baseUrl }${ url } ` , options)             .pipe(                 map(result  =>  {    ...

Error - Property 'catch' does not exist on type 'Observable<any>' in Angular. Root Cause - When you upgrade your angular application from Angular 2 or Angular 4 to Angular 6 or greater versions then you can face this error.  As From Angular 5 onwards there were many changes in rxjs. I Solution - To fix this error change your import syntax as below. change 'catch' to 'catchError'. import  { Observable }  from   'rxjs' ; import  { catchError, map }  from   'rxjs/operators' ; Thanks