Opennos master server error

[INFO] 18:31:02 -- Database has been initialized!
[INFO] 18:31:03 -- Config loaded!
[ERROR] 18:31:03 -- General Error Server
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Net.HttpListenerException: Accesso negato
at System.Net.HttpListener.AddAllPrefixes()
at System.Net.HttpListener.Start()
at Microsoft.Owin.Host.HttpListener.OwinHttpListener. Start(HttpListener listener, Func`2 appFunc, IList`1 addresses, IDictionary`2 capabilities, Func`2 loggerFactory)
at Microsoft.Owin.Host.HttpListener.OwinServerFactory .Create(Func`2 app, IDictionary`2 properties)
--- End of inner exception stack trace ---
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
at System.Reflection.RuntimeMethodInfo.UnsafeInvokeIn ternal(Object obj, Object[] parameters, Object[] arguments)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at Microsoft.Owin.Hosting.ServerFactory.ServerFactory Adapter.Create(IAppBuilder builder)
at Microsoft.Owin.Hosting.Engine.HostingEngine.Start( StartContext context)
at Microsoft.Owin.Hosting.Starter.HostingStarter.Star t(StartOptions options)
at OpenNos.Master.Server.Program.Main(String[] args) in C:\Users\User\Desktop\OpenNos-master\OpenNos.Master.Server\Program.cs:line 106