Hi Airem.
Have tried the alternative version and it works just fine. Many thanks for solving this so quickly for me, that's what I call excellent customer service!
A note for any other Mac users. Mac OS will refuse to open this game initially as it is from an unidentified developer. Simply open System Preferences, go to Security & Privacy, and you will be given the option to open the game anyway. You only need to do this once and then you should be able to open the game as normal.