I have developed a game, in order for the game to work all users need to be on the same version of the game.
Apple have complained about this and said:
Your app includes an update button or alerts the user to update the app. To avoid user confusion, app version updates must utilize the iOS built-in update mechanism.
The problem with relying on this is that it makes updating purely optional, and I am worried that if I remove this a lot of users will end up complaining that the app doesn't work and leave bad reviews.
I have seen many games where they forcefully update.
Is there a work around for this?
You can force a user to have a certain minimum version. I do it in my apps, and many other apps do it, including Clash of Clans.
Just remove the update button. You should redirect them to your app in the app store when you alert them that there is an update.
For example, your app makes a call to your server, which includes the current version. Your server responds with a message that the user must update. Your app shows the message, and when they dismiss the alert, the app redirects them to your app in the app store.
Maybe these get approved because Apple never gets to see it work like that, but certainly, they must know that Clash of Clans does it.
来源：https://stackoverflow.com/questions/37310731/apple-rejected-app-because-i-am-forcing-users-to-update-their-app-version