Steps to reproduce:
1) Create a WPF Test configured to execute against Telerik WPF Controls Examples
2) Begin 'recording', but feel free to pause the actual step recorder
3) Navigate to ScheduleView Custom ToolTip example, double-click any calendar entry
4) Delete the contents of the 'Start time' datepicker, click off of the datepicker control
5) When empty, it should show a tooltip "Value '' could not be converted."
6) Use hover-over-hightlight to expose textbox/datepicker/watermarktextbox controls and build custom verification against ToolTip message

Expected result:
The tooltip verification can be created.

Actual result:
The tooltip verification cannot be created, the default value is 'tooltip?' and clicking OK will result in an error message.