There are too many threads and not enough people reading solutions.
If you open the game and it says update and you close the game and reopen it and says update again in a never ending loop, this means that you are opening golf.exe directly. This is the application that will open when you hit the PLAY NOW button from the website (I'm trying to get that changed so we don't have this issue again).
To update, you need to open Launcher.exe.
This is likely an icon shortcut on your desktop called "WGT Launcher" if you didn't change any settings when installing it.
If it's not on your desktop, go into your files and navigate to C:/Program Files/Topgolf/WGTLauncher and run Launcher.exe from there.
Depending on your computer the Program Files folder may be different and have numbers following it like Program Files(x32), Program Files(x64), Program Files(x86), etc..
Opening the Launcher will allow you to receive the update and leave you with a nice PLAY button to open golf.exe from there.