how to implement pop up custom error message using throw new error inside workflow other than start event in alfresco version 7.0 and up

Question

The problem here is that when using alfresco version 6 the use of throw new error is able to be used as a validation method inside of a workflow, the use of throw new error here is enabling us to pop up an error message for the user stating what is the error. But, when I tried to code it into alfresco version 7.0 and up I am unable to show the error message in the pop up, the pop up will only tell failure and stating the default message. I already tried encased it with if and try and catch statement but it still only showing failure and showing the default error message in alfresco. I expecting that the result of the validation is a pop up with my custom message about the error, but sadly this only work for the start event and wont work in the other activity task in the workflow.