Assigning a different edit dialog for my workflow setting an attribute in my workitem with value WorkflowConstants.ATTRIBUTE_EDIT_DIALOG result in the followign exception

java.lang.ClassCastException: openwfe.org.engine.workitem.StringAttribute
at info.magnolia.module.workflow.inbox.Inbox$1.onSelect(Inbox.java:102)

The following piece fail due to on incoming StringAttribute value where expected String

String editDialog = StringUtils.defaultIfEmpty((String) list
.getIteratorValue(WorkflowConstants.ATTRIBUTE_EDIT_DIALOG), WorkflowConstants.DEFAULT_EDIT_DIALOG);

Filippo