See JBPM-4727.
The following commits solves the issue in master and 6.3.x respectively: master: https://github.com/droolsjbpm/kie-wb-common/commit/adcfce1d1f2d5bd2c6a197471527a5e9cbf15041 6.3.x: https://github.com/droolsjbpm/kie-wb-common/commit/430510a77a0de2718d4c892c92c115af23eae3ae
Walter Medvedeo <wmedvede> updated the status of jira JBPM-4727 to Resolved