On Thursday, January 12, 2017 8:16:58 AM EST Tomas Jelinek wrote: Actually Integer/Long entity model boxes do checks at the widget level to make sure what is entered is actually a number, however it obviously can't know anything about business logic validation. So what it does is mark the field invalid, but doesn't send the value to the actual model (it can't since the model is expecting a number and trying to send a string to a number field will cause an exception). So the backing model will contain whatever value was there before if the user entered a non number value in the field. When you click OK the business logic validation happens on the values of the model and not the values of the fields. If the model didn't change due to the above it will validate against the current value which may or may not pass depending on the validation rules.