I have version 5.1.1.3 says I have a dl but when I cant open it How can I get it

I am using Windows 10 and have Avast free. Currently I have Libra 5.1.1.3. I received the notification that 5.1.1.4 is available I am told that automatic update is unavailable within the program. So I go to the dl page and the dl comes in. I go to the dl folder and I double click on the dl and am taken me to Avast (presumably to scan) but then it will not go further. Can you help with this?
Thank you in advance.