NullReferenceException at PersonalHeliComponent.get_HeliAiError

Hello i get the following error when calling an Personal Heli:

 Anyone can help me to fix it? i dont know what to do it just stoped working. I tried to restart the Server but didnt help.

Failed to call hook 'CmdCallHeliConsole' on plugin 'PersonalHeli v1.1.7' (NullRe
ferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.PersonalHeli+PersonalHeliComponent.get_HeliAi () [0x00000] in
 <9cfff799bcfd43fb8bd94dc71032e665>:0
  at Oxide.Plugins.PersonalHeli+PersonalHeliComponent.OnInitChild () [0x00000] i
n <9cfff799bcfd43fb8bd94dc71032e665>:0
  at Oxide.Plugins.PersonalHeli+PersonalComponent.Init (Oxide.Plugins.PersonalHe
li plugin, BasePlayer player) [0x0000e] in <9cfff799bcfd43fb8bd94dc71032e665>:0
  at Oxide.Plugins.PersonalHeli.CallHeliForPlayer (BasePlayer player) [0x000c8]
in <9cfff799bcfd43fb8bd94dc71032e665>:0
  at Oxide.Plugins.PersonalHeli.CmdCallHeliConsole (ConsoleSystem+Arg arg) [0x00
1c9] in <9cfff799bcfd43fb8bd94dc71032e665>:0
  at Oxide.Plugins.PersonalHeli.DirectCallHook (System.String name, System.Objec
t& ret, System.Object[] args) [0x00643] in <9cfff799bcfd43fb8bd94dc71032e665>:0
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod meth
od, System.Object[] args) [0x00079] in <80b90e8213db44b29ec2d4111764172c>:0
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[]
 args) [0x000d8] in <ec05e0208c9149bba43236ca58fea105>:0
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] arg

Solution:
The Plugin is incompatible with TimedEvents.