Trying to start the client is a massive pain currently. A game version check failed warning pops up almost every time, and requires you to restart the client, at which point it does something odd- It does a game version check, but allows you to click play as if you're going to go into the game, resulting in the same warning.
Allowing the check to go through after the restart fixes the issue, but twice before it did not, and required a full task shut down, going into task manager and ending the task that way.
No need for User ID since this happens before you can possibly log in.