I´m having an issue with a mandatory Combo Box.  I´m using a special variable with value 0 and it must be 0, because it is a part of business rules of screen. When the validate occurs in server side the value 0 is recognized with a wrong value, and then Ajax validation returns to client side, then the combo box is paint with red and then following message error appear "obligatory field". There is a way to inform the server that my special variable with assign 0 is valid? To avoid the issue that I mention.
1)The button validation is configure with server validation 
2) The method of button is ajax.
Thanks for your attention Rafael
Hi Rafael.
The situation you reported is happening because the platform understands the value 0 as a null value, therefore, by default, it isn't accepted.
  • You can add a special scenario in the action that is called when you press the button, to make sure that when the value of the variable associated with the ComboBox is zero, it isn't invalidated;
  • You can also change the Special List value from zero to another value and add some logic to treat this value as zero;
  • Last but not least, you can choose to treat the variable as non-mandatory, and add some logic to validate the values you insert.
Please let me know if you continue to have problems regarding this subject.
Best regards,
Tito Azevedo.
I'm having a similar issue: when using a combobox set to mandatory with special value list (e.g.: 0, 1, 2, 3), no matter which value is selected, it is always considered as not valid in cliend side validation.

Currently I'm going with Tito's third suggestion, but I'm not very fond of that work-around...