Never mind I had a task in my start node wich caused the problem, so solved !!!
I haven't tested this, but while strolling through the code I saw that:
- GetTaskListCommand extends AbstractGetObjectBaseCommand.
- AbstractGetObjectBaseCommand has a method setIncludeAllVariables(boolean includeAllVariables) and setVariablesToInclude(String variablesToInclude).
I saw that you already tried to use this approach ... Perhaps Camunda can give you some help?