I've created a custom widget using the BoilerPlate as a starting point. When I test it in the Mendix test project everything works fine: refresh in client, OnChange, ListView, etc. When I'm using it in the project i run into the following problem: the widget initially loads fine, but when I click on a button on the page there is a Mendix validation error "Invalid input" below the widget. This blocks any user interaction on the page. There are no validations on the database, page or in the widget.. Any thoughts?