I have tried to successfully download this update several times and once done can only see or open the previous version. I Used the support tool and received the following File ID: KA1EE
I had a similar problem updating from 7.2 to 7.4, lt looked like it was doing it but was still 7.2 afterwards.
Here is what I did:-
Dowload an installer from here, double click the downloaded installer and it wiil install 7.4.
It will pick up your Pro licence from the old one, as long as you hadn’t uninstalled it.
(If you had uninstalled the old one then after installing 7.4 you will need to go to ‘Settings > My Subscription’ and enter your key).