Hello Sents, I have a similar requirement . We have delegated decision table rules to the user. Now when user checks-out the rule and modifies the decision table he would do a check-in. Now in our case we need to do a validation on the decision table that user just modified to ensure that there is data in at least one column of the decision table. Hence we have written an validation activity in the 'PostCheckInDialogExtension' activity. Now when the validation fails we need to display a pop-up with an appropriate message with an OK button. Could you please help me out here with my requirement. Thanks in advance.