Galactic Assault not loading after patch 1.2

I had exactly the same issue where starting GA would always try to start Kashyyyk. After a long time sitting at the loading screen, the game would return to the main menus of BF 2.

Try this, it worked for me on Xbox One S and I could then play GA and it would go through other maps, including Kashyyyk and let me play GA games. 

Exit the game by loading any other game.

Then go to the XBOX Home screen.

Highlight the game Star Wars Battlefront II, press the Menu button on your controller, and then select Manage Game. 

In the menu on the left of the screen, scroll down to Saved Data, then highlight the saved data for your gamer tag, specifically on the right and delete the 4GB of saved game data. It will warn you that the data will be recreated when the game starts next time. I did not need to delete my gamer data, only the 4 GB data file. 

Launch the game.

I did not need to restart the XBOX or log out. Probably because I first started another game to ensure BF 2 was unloaded from memory before deleting the 4 GB File.