Filter Not working when values are deleted

Hi,

On browse screen filter i had added one lookup filter as condition.
For eg. Vertical = WCF is selected and i had save the filter values and marked the filter as save filter as default but if in some scenario WCF value is deleted from database table so in that case if i try to open the browse screen i get an exception and screen is closed. Some handling need to be done if values are deleted or not present in database and screen must open wheather values of filter are present or not.

lookup

Works for me. The screen is opened with empty value in the filter parameter.
Could you provide a test project?