When starting Diablo Immortal on your iOS or Android mobile, the first thing you will want to do is connect and link your BattleNet account to the game instead of staying on a guest account. Using a BattleNet account with Diablo Immortal is really useful as it will allow you to enable cross/shared progression. For example, if you want to switch from the mobile version to the PC version or vice versa, you can continue playing without losing your data.
Likewise, if you change phones in the meantime, you'll be able to keep your save and find your character as you left it the last time you played by simply logging in with your BattleNet account on your new device. In short, the first thing you should do before embarking on your Diablo Immortal adventure is to link your account. This is what a good part of the mobile players tried when the Diablo Immortal servers opened before finding themselves faced with a major bug which simply prevented them from connecting and linking their Battle.net account…
Unable to connect or link a BattleNet account with Diablo Immortal, how to:
The developers are aware of the issue and are currently working on it. In the meantime, they advise players who are unable to link their BattleNet account to Diablo Immortal on mobile to turn off their device and turn it back on. Which is not stupid in itself since a mobile or a tablet that remains on for several days can encounter some recurring problems with apps. If that doesn't solve the problem, it's probably because the traffic on the game is too high and Blizzard's servers are having some problems... On our side, we had this bug with the following message...
Before we can connect your games, please fix the following. Unable to log in to your accounts. Connecting accounts is currently unavailable. Please try again later.
Finally, we forced the thing a little and made several attempts and it ended up passing. This proves that it is the Battle.net servers that are in question and not the user's device directly. With the weekend coming up, expect a heavy flow of players, so don't waste too much time linking your mobile account to Diablo Immortal.