Please Help

Ok so im trying to make a server using Permissionsex, and I have to questions. One is why doesn't group manager work and also whats wrong with this code. Please help thank you

groups:
Default
default: true
build: true
prefix: '&7[Member]&f'
permissions
- essentials.help
- modifyworld.chat
- modifyworld.*
- essentials.home
- essentials.sethome
- essentials.back
- essentials.tpa
- essentials.tpaccept
- essentials.tpdeny
- essentials.spawn
-essentials.warp
-essentials.listwarp
Donator
build: true
inheritance:
- Default
prefix: '&6[Donator]&f'
permissions:
- essentials.enchant
- essentials.repair
Builder:
build:true
inheritance:
- Default
prefix:'&c[Builder]&f'
permissions:
- worldedit.*
- essentials.gamemode
- signshop.*
Moderator:
build: true
inheritance:
- Default
prefix: '&b[Moderator]&7'
suffix: '&7'
permissions:
- essentials.repair
- essentials.heal
- essentials.item
- essentials.give
- essentials.fly
- essentials.kick
- essentials.mute
- essentials.tjail
- essentials.jail
- essentials.tempban
Admin:
build: true
inheritance:
- Moderator
prefix: '&4[&cAdmin&4]&e'
suffix: '&7'
permissions:
- essentials.gamemode
- essentials.ban
- essentials.unban
- essentials.ipban
- essentials.unipban
- essentials.pardon
- worldedit.*
- essentials.enchant
Owner:
build:true
inheritance:
- Admin
prefix: '&4[Owner]'
suffix: '&b'
permissions:
- '*'