New Gantt Chart Extension problem with relationLinkName in Creator

New Gantt Chart Extension problem with relationLinkName in Creator

I've burned a few hours now trying to solve this one, but no luck and there aren't any posts in the knowledge base yet:

Anytime I try to include "subRelationName" the Gantt chart fails (invalid subStartdate and subEnddate).

Works if I exclude the "subRelationName", but then I can't expand a sub-task.

input.data =
{
"reportName":"Gantt_All_Activities",
"chartSetup":
{
"dateFormat": "dd-MMM-yyyy",
"fields":
{
"taskName":"Order",
"startDate":"Activity_Date",
"endDate":"Order_Completed",
"subData":
{
"subReportName":"Gantt_Open_Item_Lists",
"subRelationName":"Activities",
"subFields":
{
"subTaskName":"PO_Number",
"subStartDate":"Welly_StartBy_Date",
"subEndDate":"Acknowledged_Complete_Date"
},
"expansion":true
}
}
}
};