if the Windows game doesn't launch, try installing the attached file (UE4PrereqSetup_x64 or 86)

if  Mac version doesn't launch:

Go to Finder, select the application (it's not from an identified developer), Control+Click on the application, select open.

or

1. Go - Utilities - Run Terminal

2. type the command : chmod +x                     (do not enter)

3. Go to the application folder     Right-click on an application that cannot be opened     Select Show Package Contents\Contents\MacOs

4. Drag the file that is in the MacOs folder to the terminal            (to Step 2) then enter

5. Back to the application folder and run the application again