Observable.of is not a function

Actually I have imports messed up. In latest version of RxJS we can import it like that:

import 'rxjs/add/observable/of';

If anybody is having this problem while using Angular >= 6 and rxjs version 6 or greater, see the answers here: Could not use Observable.of in RxJs 6 and Angular 6

In short, you need to import it like this:

import { of } from 'rxjs';

And then instead of calling

Observable.of(res);

just use

of(res);