2:  | 
    engine_ser: Pathlines - cannot advect backward in time because the specified starting time is already at the beginning of the simulation time.  The plot can successfully execute by selecting a later time step or by overriding the pathline start time. | 
    2:  | 
    engine_ser: Pathlines - cannot advect backward in time because the specified starting time is already at the beginning of the simulation time.  The plot can successfully execute by selecting a later time step or by overriding the pathline start time. |