Error Message :
After replacing a Task in a Workflow by either drag and drop or via the context menu, "Dependencies" in the Task properties are lost.
In a Workflow there is a Task with "Dependencies" in the Task Properties.
Replace this Task using drag and drop or via a right click, "Replace Task". After the replace, check the "Dependencies" again. They are lost, see the yellow pop-up in the screenshot below and compare it to the one above.