Thanks again Jim , I did the turn off and on the Dropbox option in Acudesign then when I turned on again Dropbox Asher it to allow which I did , also signed out and in again to Dropbox account , still all not working 
don’t really want to reinstall Acudesign as then all my designs and files will be lost .. hmmmmm 
really confused but I can send all my old designs to my machine via Wi-fi etc , just can’t get any new ones to Acudesign from a download