FOOTING AND PILE CONCEPT

HI ALL,

HAVE DONE A GANTRY (CANTILEVER GANTRY). HAVE ADDED PILE TO IT IN STAAD PRO...MY MODEL PASES ONLY WHEN I SEPARATE THE FRAME IN ONE MODEL AND PUT FOOTING IN OTHER MODEL

FRAME IN SEPARATE MODEL

WHY IT FIALS WHEN I COMBINE AND DO IT?

PL ADVICE 

THANKS