Vending machine error

I just bought the plugin and am getting this error in my server console. I run a carbon server

Failed to call internal hook 'OnServerInitialized' on plugin 'VehicleBuy v2.1.6' [352240293] (Object reference not set to an instance of an object) at void Oxide.Plugins.VehicleBuy.SetupVendingMachine(BaseEntity machine, VendingMachine comp, List<VMOrder> items) in /home/container/carbon/plugins/VehicleBuy.cs:line 820 at void Oxide.Plugins.VehicleBuy.SpawnVendingMachines() in /home/container/carbon/plugins/VehicleBuy.cs:line 737 at void Oxide.Plugins.VehicleBuy.OnServerInitialized() in /home/container/carbon/plugins/VehicleBuy.cs:line 596 at object Oxide.Plugins.VehicleBuy.InternalCallHook(uint hook, object[] args) in VehicleBuy.cs/Internal:line 736 Purchase Vehicles from the Shop v2.1.6 by M&B-Studios & Mevent hook 'OnServerInitialized' took longer than 100ms [138ms]