Error abort due to error: TypeError: _angular_core.InjectionToken is not a constructor

Question

I am developing aproject using VS 2017 and Angular 2 + asp.netcore. The project works fine by default, but when I import ReactiveFormsModule in app.module.ts; he gives an error

Harassment is not possible due to an error: TypeError: _angular_core.InjectionToken is not a constructor

According to the stack trace, the error is in the file .. \ ClientApp \ dist \ main-server.js.

I updated the project from Angular from 2.4 to Angular 4.0. I cannot understand why imports should cause such an error.

Answer 1

, , 3.3.7 4.0.0-beta2.

Visual Studio ( 15.5.1) .