Can't Edit Multiverse Core config.yml file

When I edit and save it, It reverts back to the default settings again.

Here is the config.yml text-

------------------------------------------------------------------------- #

# This is the MV2 Config. If you mess it up, copy the values out #

# delete it, and it will be regenerated. Then use the ingame interface #

# to add your values back via the "/mv conf" command. #

# When in-game, simply type: "/mv conf ?" for help. #

# A config with explanations can be found here: #

# https://github.com/Multiverse/…erse-Core/wiki/config.yml #

# #

# #

# IMPORTANT !! IMPORTANT !! IMPORTANT !! IMPORTANT !! IMPORTANT !!IMPORTANT #

# #

# Do NOT delete this line from your config!!!! #

# ==: com.onarandombox.MultiverseCore.MultiverseCoreConfiguration #

# #

# IMPORTANT !! IMPORTANT !! IMPORTANT !! IMPORTANT !! IMPORTANT !!IMPORTANT #

# ------------------------------------------------------------------------- #

multiverse-configuration:

==: com.onarandombox.MultiverseCore.MultiverseCoreConfiguration

enforceaccess: 'false'

prefixchat: 'true'

prefixchatformat: '[%world%]%chat%'

useasyncchat: 'true'

teleportintercept: 'true'

firstspawnoverride: 'true'

displaypermerrors: 'true'

globaldebug: '0'

silentstart: 'false'

messagecooldown: '5000'

version: '2.9'

firstspawnworld: world

teleportcooldown: '1000'

defaultportalsearch: 'false'

portalsearchradius: '128'

autopurge: 'true'

idonotwanttodonate: 'false'

Thank You.

Sorry for the late reply. Yes, it does revert back when I start the server. not immediately.