Disabling online mode on a Minecraft server lets it run without verifying players against Mojang’s authentication servers, allowing cracked/offline clients to join your server.
Players can also change their usernames to join the server using a different user's account. Please ensure you install an authentication system such as:
The AuthMeReloaded plugin
The EasyAuth Fabric mod
The Nedologin or SimpleLogin Forge mods
Disabling online mode also prevents skins from loading in. To restore profile skins, you will need to install:
The SkinsRestorer plugin
The FabricTailor or Everlasting Skins for modded servers.
Turning Off Online Mode
To turn off online mode:
Access the Paradise Panel.
Stop the server.
In the Files tab, open the
server.propertiesfile.Locate the
online-mode=trueline.Set it to
online-mode=falseSave the changes.
Start the server.