Use TrustedRedirectResponse Error on Multilingual Setup

I received the following error while setting up a multilingual website:

Redirects to external URLs are not allowed by default, use \Drupal\Core\Routing\TrustedRedirectResponse for it.

Here is the sequence to create this error:

• Install new 8.0.1 website using English
• Enable Language Translation and Language Modules
• Allow Trusted Hosts: localhost, www.localhost& es.localhost in settings.php
• Add Spanish language
• Set Detection & selection > Domain to www for English and es for Spanish & Save Configuration

I've done this several times in beta.

As a side note. On the "Detection & selection" screen, the user is entering "sub-domains" not "Domains" as the screen says. In this example: Example: Specifying "de.example.com" as language domain for German will result in an URL like "http://de.example.com/contact"., de is a sub-domain of example.com/. This screen should likely be changed.