Search Widget error

Have a map layer based on XY Events from a table.
Add a Search Widget on the layer. The first search works when the map web opened, by spatial or by attribute both work.
If I clear last search, do second Search, it has the error: [RPC Fault faultString="Invalid or missing imput parameters." faultCode="400" faultDetail=""]

Added Search Widget on other layers, like town boundary, street etc, All work fine.

What can cause the problem?

Thanks.