Exception status field does not enable required fields for HT forms.

In a human task's form, if a user selects a specific value in a drop-down box then two read-only text boxes need to become editable. E.g.: When user select “Exception Status” field as "Escalated" from the drop-down the other field that is “Open Page ID” and “Date Escalated” should be enabled and editable to users in JBPM Form Modular.