Observable is not accepting Catch

To use the 'Catch' operator, you need to import it from the rxjs library in this way:

import 'rxjs/add/operator/catch';

So you'll be able to use it.

As the Observable is asynchronous, try / catch does not work. You should set an error callback as the example below angular documentation :

myObservable.subscribe({
  next(num) { console.log('Next num: ' + num)},
  error(err) { console.log('Received an errror: ' + err)}
});