In Test Studio try selecting multiple steps containing If..Else logical steps and add them to a test as step and you will get the following error:

Unexpected error occurred and will be reported to Telerik: No Collection

The stack in the log follows:

[01/27 15:31:37,Telerik.TestStudio.exe(8984:1),TestStudio] TestExplorerController.ExecuteCommand() : EXCEPTION! (see below)
     Outer Exception Type: System.InvalidOperationException
     Message: No collection
     HRESULT: 0x80131509 (Official ID (if app.) = COR_E_INVALIDOPERATION, Error Bit = FAILED, Facility = FACILITY_URT, Code = 5385)
     Call Stack:
          at Telerik.Windows.Data.DataItemCollection.get_Item(Int32 index)
          at ArtOfTest.WebAii.Design.UI.TestExplorerController.AddStep(AutomationStep step, TreeListViewDropPosition relativeLocation, StepViewModel referenceStep, Boolean setAsCurrentRecordIndicator, Boolean addToUndoStack)
          at ArtOfTest.WebAii.Design.UI.TestExplorerController.CreateTestAsStep()
          at ArtOfTest.WebAii.Design.UI.TestExplorerController.ExecuteCommand(ICommand command, Object parameters)

Short video demonstration of the problem: http://screencast.com/t/94nRDcCB19s0