Bukkit

What steps will reproduce the problem?

What is expected, and what do you get instead
I use multiverse, i did all the steps , and i was really carefully , and when i do the command to create the world, it saus ''An Internal Error ...''

What version are you using?
my server is 1.8.8

Do you have an error log of what happened?
20.03 10:03:57 [Server] INFO Zegiond issued server command: /mv create skyland normal -g IsleWorldGen
20.03 10:03:57 [Server] INFO Zegiond: Starting creation of world 'skyland'...
20.03 10:03:57 [Server] INFO Loading World & Settings - 'skyland' - Env: NORMAL - Type: NORMAL & generator: IsleWorldGen
20.03 10:03:57 [Server] INFO -------- World Settings For [skyland] --------
20.03 10:03:57 [Server] INFO Anti X-Ray: true
20.03 10:03:57 [Server] INFO Engine Mode: 1
20.03 10:03:57 [Server] INFO Hidden Blocks: [14, 15, 16, 21, 48, 49, 54, 56, 73, 74, 82, 129, 130]
20.03 10:03:57 [Server] INFO Replace Blocks: [1, 5]
20.03 10:03:57 [Server] INFO Mob Spawn Range: 4
20.03 10:03:57 [Server] INFO Nerfing mobs spawned from spawners: false
20.03 10:03:57 [Server] INFO Cactus Growth Modifier: 100%
20.03 10:03:57 [Server] INFO Cane Growth Modifier: 100%
20.03 10:03:57 [Server] INFO Melon Growth Modifier: 100%
20.03 10:03:57 [Server] INFO Mushroom Growth Modifier: 100%
20.03 10:03:57 [Server] INFO Pumpkin Growth Modifier: 100%
20.03 10:03:57 [Server] INFO Sapling Growth Modifier: 100%
20.03 10:03:57 [Server] INFO Wheat Growth Modifier: 100%
20.03 10:03:57 [Server] INFO NetherWart Growth Modifier: 100%
20.03 10:03:57 [Server] INFO Entity Activation Range: An 32 / Mo 32 / Mi 16
20.03 10:03:57 [Server] INFO Entity Tracking Range: Pl 48 / An 48 / Mo 48 / Mi 32 / Other 64
20.03 10:03:57 [Server] INFO Hopper Transfer: 8 Hopper Check: 8 Hopper Amount: 1
20.03 10:03:57 [Server] INFO Random Lighting Updates: false
20.03 10:03:57 [Server] INFO Structure Info Saving: true
20.03 10:03:57 [Server] INFO Sending up to 10 chunks per packet
20.03 10:03:57 [Server] INFO Max Entity Collisions: 8
20.03 10:03:57 [Server] INFO Custom Map Seeds:  Village: 10387312 Feature: 14357617
20.03 10:03:57 [Server] INFO Max TNT Explosions: 100
20.03 10:03:57 [Server] INFO Tile Max Tick Time: 50ms Entity max Tick Time: 50ms
20.03 10:03:57 [Server] INFO Item Despawn Rate: 6000
20.03 10:03:57 [Server] INFO Item Merge Radius: 2.5

Please provide any additional information below.

It says ''starting creating world''
and below that is says the error.. and when i do ./mv list there is nothing , only my default worlds...

That isn't the full log.