Machine is a Haas VF3 with auto pallet system. Both pallets are on the outside table. M50 won't load either one. What do you have to do to get a table on deck.
Assuming that the table is in line with one of them, you need to manually move the pallet into position onto it. There is a tool that should have been included with the machine to do this. It is a piece of hex stock with an end turned down and a key in the end. You insert it into the gear on the end of the chain farthest from the machine and put a wrench on the hex. Make sure you hold the key into the keyway on the gear, once it gets stripped it won't work without recutting the end flat again.
You will need to move the chain all the way around until the cam on it hits the limit switch, not just till the pallet is on the table.
I don't remember the exact M code to lock/unlock the pallet, but I think it's M17 or M18
Once locked to the table, then close the door and run an M50 - it should work
Apparently I don't know anything, so please verify my suggestions with my wife.