Problem on validation in Listview

I have made clear of some problem, but still can not solve the 2 points

1. When error occurs, the tooltip always shows "Exception has been thrown by the target of invocation" instead of proper content defined in the exception string (In this case, it should be "Invalid location name")

2. Validation does not work whenever you input expected value or invalid value (ie.When you input "America" or "France" in the textfield, then lose keyboard focus, textfield is still wrapped with red rectangle which indicate it is an invalid value)

Could anyone give me suggestion? thanks