Custom message for error while validating expected inputs

Hi everybody,

I’m using bonita 7.2. When I got a validation error in form, I got an error popup saying:

“Error while trying to execute the task. Some required information is missing (not contract not fullfilled)”

Is it possible to customize this message?
I tried to add a costraint on contract variable, typing an error message, but I can’t see it nowhere…
Thank you all for helping me.

Michele