I have actually solved it! yes little old me!!!!
So go to your download folder where the app is and right click, go to properties.
Under 'General' go to the bottom where it says Security and click on the 'unblock' button, then apply and ok.
Continue through any pop ups and bobs your uncle you're in!!! <3<3 this was also driving me utterly bonkers as to why i couldn't download adobe illustrator!!!!!!!
Hope this helps at least one other person!