'Uncaught Error: Can't resolve all parameters for' runtime error when upgrading from Angular 4 to 5.0.1

Question

This is fine in Angular 4.x, just not Angular 5.0.1. This project was generated with Angular CLI.

compiler.js:466 Uncaught Error: Can\'t resolve all paramet         


        

Answer 1

In Angular 5 Update blog post the author mentions that they are using a static injector instead of a reflection based one and mentions that the reflection polyfills are no longer needed but in my case it was.

If you removed the polyfills for reflections try adding them again:

import 'core-js/es6/reflect';
import 'core-js/es7/reflect';

I hope it woks for you as well.

Answer 2

In my case, for Angular 6.1 migration, it was a missing:

import "reflect-metadata";
import "zone.js";

inside the bootfile.

Answer 3

The error mentions that you're using a wron constructor for RegistrationService.