Double click to install doesn't do anything!

I am trying to install a free trial of a programme on creative cloud, but cannot get past the creative cloud installer window which says 'double click to install. I click, allow web app, enter password to allow changes and then nothing happens...

I have tried deleting the installer and re-downloading it but this doesn't change anything.

I am using mac os sierra 10.12.1 on a 2.5ghz i5 processor.

any ideas??