ERROR in TypeError: Cannot read property 'flags' of undefined

Question

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

Answer 1

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