I created a custom papersize A3 ++ ( 530 x 297 mm / landscape ) in Layout. I also added the custom A3++ papersize in the Adobe PDF settings. So far, so good !!
Problem is that in prints in portrait ???
Strange thing is that everytime i open the file i can work in landschape mode, but in the document setup portrait is activated. So I manually set it back to landscape and checked print preview where it shows in portrait. See the attachment.
What would you do ?