I have already gone through similar posts but nothing seems to work for me. I'm running Indigo Studio on Windows 8.1. Silverlight 5 was already installed on my computer along with Visual Studio.

Indigo log

2016-06-09 15:01:59.77 [dcde38] [Debug] NativeHost: Created web browser
2016-06-09 15:01:59.81 [dcde38] [Info ] NativeHost: Initializing native host
2016-06-09 15:01:59.84 [dcde38] [Debug] NativeHost: Loaded settings file
2016-06-09 15:02:02.21 [dcde38] [Warn ] CefProcess: CEF Devtools support was requested but <user>\AppData\Local\Infragistics\Indigo Studio\en-GB.pak was not found.
2016-06-09 15:02:02.21 [dcde38] [Debug] CefProcess: Devtools disabled.
2016-06-09 15:02:02.60 [dcde38] [Debug] NativeHost: Launched CEF process
2016-06-09 15:02:03.30 [dcde38] [Debug] ResourceServerHttp: Opened resource server on URI: 'http://localhost:7890/'.
2016-06-09 15:02:03.30 [dcde38] [Debug] NativeHost: Created resources server
2016-06-09 15:02:03.81 [dcde38] [Debug] ResourceServerHttp: Serving request: '/'
2016-06-09 15:02:05.66 [dcde38] [Debug] NativeHost: Created preview runner
2016-06-09 15:02:05.66 [dcde38] [Debug] NativeHost: Native host initialized
2016-06-09 15:02:05.81 [dcde38] [Debug] ResourceServerHttp: Serving request: '/Silverlight.js'
2016-06-09 15:02:05.81 [dcde38] [Debug] ResourceServerHttp: Serving request: '/styles.css'
2016-06-09 15:02:05.83 [dcde38] [Debug] ResourceServerHttp: Serving request: '/SplashProgress.gif'
2016-06-09 15:02:05.83 [dcde38] [Debug] ResourceServerHttp: Serving request: '/InfragisticsLogo.png'
2016-06-09 15:02:05.85 [dcde38] [Debug] ResourceServerHttp: Serving request: '/splashLoading.jpg'
2016-06-09 15:02:06.86 [dcde38] [Debug] ResourceServerHttp: Serving request: '/html5shiv.js'
2016-06-09 15:02:08.16 [dcde38] [Debug] ResourceServerHttp: Serving request: '/bg.png'
2016-06-09 15:02:08.66 [dcde38] [Debug] ResourceServerHttp: Serving request: '/Indigo.xap'
2016-06-09 15:02:10.33 [dcde38] [Info ] NativeHost: SL plugin downloaded

When trying http://localhost:7890 in browser, it says that I need to install Silverlight 5, which, like I said, is already installed.

When trying to close the Indigo studio window, an exception is thrown with the following stack trace.

System.ArgumentNullException: Value cannot be null.
Parameter name: value
at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)
at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value, JsonSerializerSettings settings)
at Infragistics.Prototypes.Shell.Win.SilverlightInterface.TryJsonInvoke(String methodName, Object[] args)
at Infragistics.Prototypes.Shell.Win.SilverlightInterface.HasUnsavedChanges()
at Infragistics.Prototypes.Shell.Win.NativeHost.OnNativeHostClosing(Object sender, CancelEventArgs args)
at System.Windows.Forms.Form.OnClosing(CancelEventArgs e)
at System.Windows.Forms.Form.WmClose(Message& m)
at System.Windows.Forms.Form.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)