Failed to call hook 'OnServerInitialized'

Failed to call hook 'OnServerInitialized' on plugin 'ServerPanel v2.0.5' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.ServerPanel.LoadImages () [0x00145] in <8dd12aa041c446e58cebcabdee834a87>:0
  at Oxide.Plugins.ServerPanel.InitializePlugin () [0x0001c] in <8dd12aa041c446e58cebcabdee834a87>:0
  at Oxide.Plugins.ServerPanel.OnServerInitialized () [0x000ac] in <8dd12aa041c446e58cebcabdee834a87>:0
  at Oxide.Plugins.ServerPanel.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x0117a] in <8dd12aa041c446e58cebcabdee834a87>:0
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <42f9bedc659b4f4786eb778d3cd58968>:0
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in <112d89ea5d3348c8b949af0ab1a866d2>:0
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <112d89ea5d3348c8b949af0ab1a866d2>:0

I buy the plugin today and put it in my folder thats it. I try also to intsall your shop first the shop is working but the panel still have this error even after restart. 

I need to install the plugin first to chose a template or not? /sp.install  (or) /welcome.install are not working.

the command dont work at all there is no permission warning 

I reinstall oxide and add only the panel and image plugin looks like it works now Im sorry to waste your time but I have no idea why it not work before