If you are on Windows, try this. Close the game, navigate your way here in windows explorer...
C: \ Program Files (x86) \ Topgolf \ WGTLauncher
...rename the golf folder, then try running the game again to see if it updates successfully.
If the update is successful, you can then go back into windows explorer and delete the golf folder that you renamed. There should be a new golf folder there, don't delete that one.