Powerviot open Error in SharePoint 2013

Testing Service C2WTS
+-Service C2wts found
+-Service C2wts is running
+-Path of Service:c:\program Files\Windows Identity Foundation\v3.5\c2wtshost.exe
+ Config File:c:\program files\windows Identity foundation\v3.5\c2wtshost.exe.config
+-Service logon:system\nt Authority
-----start of config file----
<?xml version= "1.0"?>
<configuration>
<configSections>
<section name= "Windowstokenservice" type= " Microsoft.IdentityModel.WindowsTokenService.Configuration.WindowsTokenServiceSection, Microsoft.IdentityModel.WindowsTokenService, version=3.5.0.0, culture=neutral, publickeytoken=31bf3856ad364e35 "/ >
</configSections>
<startup>
<supportedruntime version= "v4.0"/>
<supportedruntime version= "v2.0.50727"/>
</startup>
<windowsTokenService>
<!--
By default no callers is allowed to use the Windows Identity Foundation Claims to NT Token Service.
Add the identities wish to allow below.
-
<allowedCallers>
<clear/>
<add value= "WSS_WPG"/>
</allowedCallers>
</windowsTokenService>
</configuration>
-----End of config file----
Retrieving security groups/users allowed to use the Service from config file
+-WSS_WPG
Trying to login .....
Using provided credentials to login
C2WTS could not provide a valid Windows tokens. Reason:WTS0003:The caller is not a authorized to access the service.

Server stack trace:
at System.ServiceModel.Channels.ServiceChannel.ThrowIfFaultUnderstood (Message reply, Messagefault Fault, String action, messageversion version, Faultconverter faultconverter)
at System.ServiceModel.Channels.ServiceChannel.HandleReply (Proxyoperationruntime operation, proxyrpc& RPC)
at System.ServiceModel.Channels.ServiceChannel.Call (String action, Boolean oneway, proxyoperationruntime operation, object[] ins, object[] outs, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService ( IMethodCallMessage Methodcall, proxyoperationruntime operation)
at System.ServiceModel.Channels.ServiceChannelProxy.Invoke (IMessage message)

Exception rethrown at [0]:
At System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage (IMessage reqmsg, IMessage retmsg)
At System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke (messagedata& msgdata, Int32 type)
At Microsoft.IdentityModel.WindowsTokenService.S4UClient.IS4UService_dup. Upnlogon (String UPN, Int32 pid)
At Microsoft.identitymodel.windowstokenservice.s4uclient.<>c__displayclass1.<upnlogon>b__0 ( Is4uservice_dup Channel)
At Microsoft.IdentityModel.WindowsTokenService.S4UClient.CallService (Func ' 2 contractoperation)
At C2WTSTest.Form1.button2_Click (Object sender, EventArgs e)

Now verifying if user wtc\setup.moss have rights on C2WTS
+-User Wtc\setup.moss have no access to the service
Analysis Complete * * *

Powerviot open Error in SharePoint 2013