How to reproduce: Check the attached project and video

Workaround: force an update in the MapElement
Public Class RadForm1

    Private bingKey As String = ""
    Dim myTimer As Timer
    Public Sub New()

        InitializeComponent()
        Dim bingProvider As BingRestMapProvider = New Telerik.WinControls.UI.BingRestMapProvider()
        bingProvider.UseSession = True
        bingProvider.BingKey = bingKey

        AddHandler bingProvider.SearchCompleted, AddressOf bingProvider_SearchCompleted

        Me.RadMap1.Providers.Add(bingProvider)

        myTimer = New Timer
        myTimer.Interval = 500
        AddHandler myTimer.Tick, AddressOf OnMyyTimerTick
    End Sub

    Private Function OnMyyTimerTick() As Object
        myTimer.Stop()
        Me.RadMap1.MapElement.InvalidateMeasure(True)
    End Function

    Private Sub bingProvider_SearchCompleted(sender As Object, e As SearchCompletedEventArgs)

        myTimer.Start()

    End Sub
End Class

To reproduce:
- Create a shape with QGIS and add it to RadMap using the approach described in the documentation: http://docs.telerik.com/devtools/winforms/map/file-readers/esri-shapefile-reader

Error:

System.ArgumentException was unhandled
  HResult=-2147024809
  Message=An item with the same key has already been added.
  Source=mscorlib
  StackTrace:
       at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
       at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
       at Telerik.WinControls.UI.DbfHeader.CreateExtendedPropertySet()
       at Telerik.WinControls.UI.DbfReader..ctor(Stream stream, ExtendedPropertySet propertySet, Encoding encoding)
       at Telerik.WinControls.UI.ShapeFileReader.Read(ShapeFileReaderParameters parameters)
       at _1125357MapShapeFiles.RadForm1..ctor() in d:\Projects\1125357MapShapeFiles\RadForm1.cs:line 37
       at _1125357MapShapeFiles.Program.Main() in d:\Projects\1125357MapShapeFiles\Program.cs:line 17
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: