Question Your configuration must be fixed before PEX will enable

Anybody know why this is happening? this is my current config

Code:

groups:
  Guest:
    build: false
    permissions:
    - essentials.help
    - essentials.rules
    - essentials.motd
    - modifyworld.chat
    options:
      prefix: '[Guest] '
      default: true
  Member:
inheritance:
- Guest
    build: true
    permissions:
    - essentials.help
    - essentials.rules
    - essentials.motd
    - essentials.afk
    - essentials.back
    - essentials.back.ondeath
    - essentials.depth
    - essentials.delhome
    - essentials.help
    - essentials.home
    - essentials.kit
    - essentials.kit.tools
    - essentials.list
    - essentials.mail
    - essentials.mail.send
    - essentials.me
    - essentials.motd
    - essentials.msg
    - essentials.ping
    - essentials.r
    - essentials.rules
    - essentials.seen
    - essentials.sethome
    - essentials.signs.use.disposal
    - essentials.spawn
    - essentials.suicide
    - essentials.tpa
    - essentials.tpaccept
    - essentials.tpahere
    - essentials.tpdeny
    options:
      prefix: '&2[&aMember&2]&7 '
      default: false
  VIP:
    inheritance:
    - Member
    build: true
    permissions:
    - essentials.help
    - essentials.rules
    - essentials.motd
    options:
      prefix: '&6[&eVIP&6]&7 '
      default: false
 Donator:
    inheritance
- Member
    build: true
    permissions:
   - essentials.fly
    options:
      - prefix: '&6[&eDonator&6]&7 '
  Mod:
    inheritance:
    - VIP
    - Member
    build: true
    permissions:
    - essentials.sethome.multiple.staff
    - essentials.helpop
    - essentials.home.others
    - essentials.nick
    - essentials.warp
    - essentials.warp.list
    options:
      prefix: '&1[&9Mod&1]&f '
      default: false
  Admin:
    inheritance:
    - Mod
    - VIP
    build: true
    permissions:
    - essentials.gamemode
    - essentials.give
    - essentials.god
    options:
      prefix: '&9[&bAdmin&9]&f '
      default: false
  Owner:
    build: true
    permissions:
    - '*'
    options:
      prefix: '&6[&4Owner&6]&f '
      default: false
users:
  exampleminecraftname:
    group:
    - Owner
  exampleminecraftname2:
    group:
    - Admin
schema-version: 1

 

Formatting is important. Add four spaces before inheritance and 6 spaces before Guest.

[Edit] There's more. Go down the file and make sure everything is indented correctly.