in dnn7.3 when i want to go site-setting page i receive the following errow

Selection out of range Parameter name: value

here is the log

DotNetNuke.Services.Exceptions.PageLoadException: Selection out of range
Parameter name: value ---> System.ArgumentOutOfRangeException: Selection out of range
Parameter name: value
   at Telerik.Web.UI.RadComboBox.PerformDataBinding(IEnumerable dataSource)
   at Telerik.Web.UI.RadComboBox.PerformSelect()
   at DotNetNuke.Web.UI.WebControls.DnnSkinComboBox.OnLoad(EventArgs e)
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   --- End of inner exception stack trace ---

please figure out and help to solve this issue

Regards, 

Mohammmad