Error when trying to inject a service into an angular component “EXCEPTION: Can't resolve all parameters for component”, why?

Question

I\'ve built a basic app in Angular, but I have encountered a strange issue where I cannot inject a service into one of my components. It injects fine into any of the three o

Answer 1

In addition to the missing @Injectable() decorator

Missing @Injectable() decorator in abstract class produced the Can't resolve all parameters for service: (?) The decorator needs be present in MyService as well as in the derived class BaseService

//abstract class
@Injectable()
abstract class BaseService { ... }

//MyService    
@Injectable()
export class MyService extends BaseService {
.....
}