[Forums] Select2 validation error message not shown and no red border on control

I have select2 on a listBox.
When valid property of the control is false and ValidationMessage is filled ("Required field!") the message is not shown on the form and the control does not get the red border.
So the user does not know what is wrong.

I have tested it in a clean eSpace with the londonFixed theme.
Placed the Form control on the screen.
On the Form two fields:
- TextBox
- ListBox with Select2
Submit button