When I save a node - I get an error 500

I get following errors when trying to access a node that have an image in it - times 3 from 3 different IPs (all Fastly IPs)

InvalidArgumentException: The URI '//d3ocrpywcc4gay.cloudfront.net/sites/default/files/hero/2016-04/autohjaelp_trailer.jpg' is invalid. You must use a valid URI scheme. i Drupal\Core\Url::fromUri() (linje 276 af /var/www/html/core/lib/Drupal/Core/Url.php).

And I get these messages from the fastly module also in recent reports:
Successfully purged the key config:cdn.settings. Purge ID: 296-xxxxx-xxxxx.

In the screenshot you see the logs filed when I did a Activated of the preconfigured CDN module and after the 500's deactivated CDN in the settings again both on the Status tab in CDN module UI.

You might also need to know that the way we have the sites set op is like this:

subdomain.prod.domain.dk (The drupal server)
subdomain.domain.dk (fastly)

The Drupal server is only accessible from fastlys servers.

I don't have the purge module installed.

This is my make file

# Subsite makefile
# ----------------
# drush make base.make <target directory>
# drush make xxxx.make.yml .

#
# API version
# ------------

api: 2

# Core version
# ------------
core: "8.x"

# Set contrib directory
defaults:
  projects:
    subdir: "contrib"


# Fetch translations
translations:
  - da

# Core project
# ------------
projects:
  drupal:
    type: "core"
    version: "8.1.2"

  # ------------
  # development modules
  # ------------
  admin_toolbar:
    version: "1.15"
    subdir: development

  coffee:
    version: "1.0-beta1"
    subdir: development

  devel:
    version: "1.x-dev"
    subdir: development

  features:
    version: "3.0-alpha6"
    subdir: development

  # ------------
  # Contrib modules
  # ------------

  allowed_formats:
    version: "1.0"

  cdn:
    version: "3.0-alpha1"

  config_update:
    version: "1.1"

  crop:
    version: "1.0-rc1"

  ctools:
    version: "3.0-alpha26"

  editor_advanced_link:
    version: "1.2"

  editor_file:
    version: "1.1"

  embed:
    version: "1.0-rc2"

  entity:
    version: "1.0-alpha3"

  entity_embed:
    version: "1.0-alpha1"

  fastly:
    version: "3.0-alpha2"

  field_group:
    version: "1.0-rc4"

  git_deploy:
    version: "2.x-dev"

  #geolocation:
  #  version: "1.5"

  imagemagick:
    version: "1.0-alpha2"

  image_widget_crop:
    version: "1.0"

  libraries:
    version: "3.x-dev"

  metatag:
    version: "1.0-beta9"
# From beta 8    patch: "https://www.drupal.org/files/issues/metatag-n2725895-2.patch"

  pathauto:
    version: "1.0-alpha3"

  # Info about the current state of the module https://github.com/md-systems/redirect
  redirect:
    download:
      url: "git://github.com/md-systems/redirect.git"
      branch: "8.x-1.x"

  search_api:
    version: "1.0-alpha15"

  seckit:
    version: "1.x-dev"

  simplify:
    version: "1.0"

  token:
    version: "1.0-alpha2"

  weight:
    version: "3.0"

  # --------------
  # Custom modules
  # --------------

  search_api_algolia:
    download:
      type: git
      url: "https://github.com/fdmweb/search_api_algolia.git"
    destination: custom

  unset_html_head_link:
    download:
      type: git
      url: "https://github.com/fdmweb/unset_html_head_link.git"
    destination: custom

I am not saving a new file with it.
Just going to a node with a image and then trying to save it.