2.78 firmware will not go past initializing

hi all,

i have flashed my apm2.5 to plane 2.78b all was working ok, but then when i went to power cycle the apm is was not initializing and picking up compass and gps, when i plug into the planner it says initializing and will not go passed, if i flash to any other firmware like copter (quad etc) it works fine…
used the latest mac and windows planner to flash

any ideas?

the planner software also states after a short time link lost and the little green square in the planner where the mode is indicated changes to red