Thanks Marten. Before you responded my over-zealous self laid down the shekels for WorldJetways from Aerosoft, which was the reason I was after your wonderful SAM in the first place. I am pleased to advise that it works a treat on my mid-2011 iMac running MacOS 10.13. I understand that SAM may not work with other programs for me, but that is OK.
Just sayin'