Error when trying to run an Outbreak (/outbreak)

Hello guys,

Having this error message when trying to tun the outbreak command. Not sure what it is. Anyone would help pls?

Thanks a lot.

Failed to call hook 'cmd_outbreak' on plugin 'Diseases v2.1.0' (IndexOutOfRangeException: Index was outside the bounds of the array.)
  at Oxide.Plugins.Diseases.cmd_outbreak (Oxide.Core.Libraries.Covalence.IPlayer player, System.String command, System.String[] args) [0x00000] in <d33f0a1b90dd494db65b3d5552b47767>:0
  at Oxide.Plugins.Diseases.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00d16] in <d33f0a1b90dd494db65b3d5552b47767>:0 , 8kb/s out
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <3606d2af539c45e4b5c61658e6a8b307>:0
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <c2afd8354b8b4f3ca451cf5a1aa111c3>:0
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <c2afd8354b8b4f3ca451cf5a1aa111c3>:0​

Not sure why, but the:

/disease outbreak <disease> <attempts?>​

wont do anything at all. It says the virus infected 0 players. Even if I set 100 attempts, the plugin would try only once. I am the only player on the server yet, is there a minimum limit to start an outbreak please?

Thanks for your help