Trying to run a test with a handle SaveAs dialog for a WPF application handles the dialog then errors out with:
Failure Information: 
~~~~~~~~~~~~~~~
Exception thrown executing coded step: '[HandleSaveAsDialog_CodedStep] : LeftClick on OpenCustomTextblock'.
InnerException:
System.NullReferenceException: Object reference not set to an instance of an object.
   at ArtOfTest.WebAii.Win32.Dialogs.BaseDialog.WaitUntilAnyHandled(IEnumerable`1 dialogs, Int32 handleCount, Int64 timeoutMilliseconds, Boolean resetHandleCount)
   at ArtOfTest.WebAii.Win32.Dialogs.BaseDialog.WaitUntilHandled(Int32 handleCount, Int32 timeout, Boolean resetHandleCount)
   at ArtOfTest.WebAii.Win32.Dialogs.BaseDialog.WaitUntilHandled(Int32 timeout)
   at TestExamplesProject.HandleSaveFileDialog.HandleSaveAsDialog_CodedStep() in e:\Users\Dad\Documents\Test Studio Projects\TestExamplesProject\HandleSaveFileDialog.tstest.cs:line 63

This happens for either the non-coded or coded test step. Attached is a sample WPF app and test to repro the problem.