Updated Drupal to 8.6. This goes with the following updates because it's possible...

[yaffs-website] / web / core / profiles / demo_umami / config / install / block.block.umami_account_menu.yml

langcode: en
status: true
dependencies:
  config:
    - system.menu.account
  module:
    - system
  theme:
    - umami
id: umami_account_menu
theme: umami
region: pre_header
weight: -6
provider: null
plugin: 'system_menu_block:account'
settings:
  id: 'system_menu_block:account'
  label: 'User account menu'
  provider: system
  label_display: '0'
  level: 1
  depth: 1
visibility: {  }