Predecesor Tasks across Plan Types

I am trying to understand the error message: Work item predecessors planned for different iterations are ignored in the current work item schedule

I get this error message because I have a task defined in the Release Plan and a task defined in a child Phase Plan.  The task in the child phase plan has the constraint from the Parent Release Plan and its predecessor.

If i have a task that is scheduled for later a later phase but has a task dependency to complete before the phase begins.  Is it better to include the task in the later phase and set it due date before the phase starts? Or put the task in an earlier phase and not have the dependency any longer.