Custom task defined by new work item definition has been created in jBPM Designer as some unknown task with TaskType="My" which is a substring of the work item's name. It does not contain any Data I/O nor Assignments, it does not show the icon defined in WID file and the process definition is broken so badly, that even bpmn2 source cannot be displayed.

Clicking on View node source leads to error:
No enum constant org.jbpm.designer.bpmn2.impl.Bpmn20Stencil.Task_My

Steps to Reproduce:
1. upload an icon
2. create a new work item definition, change the icon and save it
3. create a new bpmn2 process
4. use the new service task, see it's properties
5. try to watch the bpmn2 source.

Moreover, this corrupted process definition can be saved without any problem - at least this jBPM Designer says. After reopening the definition, there is only a start node (see the screenshot for a process definition before saving).
Attaching also my work item definition file.