In Baldurs Gate (North Central) I cannot get into the palace. Do I need to do something to open the gate first or is it an error in my game. I need to get in thier to complete the misson the Thieves Guild gave me. Can anyone help? Thanks.

The Ducal Palace isn't where you have to go for the skyship parts. You should be at an estate for that quest, which is in the same screen as the fair (in the NE corner), and has a gate that your thief can get into pretty easily. It's either there or n the next screen to the north that you enter, pretty sure it's there.

success. Thanks.