deviceUniqueIdentifier Changing on App Update

Unity Engine
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1

Hi,

We are finding that a number of users have their deviceUniqueIdentifier change upon updating our game through the App Store. We have a sample size of 5 million users for this app, and each time we release an update approximately 300 of them receive a new deviceUniqueIdentifier. We have confirmed that all other variables are equal-- all builds come from the same Unity version, the users are running the same version of iOS both before and after updating the app, and the users have not uninstalled the app at any point. Simply downloading the app update causes the ID change.

Affected users seem to be distributed evenly between iOS 7 and 8, and the Unity version is 4.6.4 f1.

I know that deviceUniqueIdentifier is supposedly tied to the advertising ID, but I don’t see any literature to suggest that simply updating an app could ever cause the advertising ID to reset. Have any other publishers experienced this? Does Unity support have any thoughts?

Thanks so much!

2

Is it possible they are deleting and reinstalling as this does give a different id I believe.

3

Thanks andy. Nope, as I mentioned, we confirmed that the users have not uninstalled the app at any point. All local data is still intact; the ID has simply changed. We’ve been making iOS games with Unity for over 5 years and there isn’t much that surprises us anymore, but this is not something we are able to explain. Other than the big switch from MAC address to advertising ID, we’ve never seen spontaneous changes like this in the deviceID. It seems to be a relatively new phenomenon within the last few months, too.

4

Hey WermHat, have you by any chance found the issue? It appears that my app is in the same situation with 2017.1.0f3.

5

We never did. We’re also not on 2017 so I can’t comment on that specific situation :frowning:

6

Have you submitted a bug?

7

It’s impossible to recreate, so we didn’t bother. Maybe 1 out of every 500 users will experience it once over the lifetime of playing the game.

8

I spotted a bug recently that only manifested itself in an app downloaded from the iOS AppStore.

Basically Application.installMode never returned Store when it should have. I couldn’t send a repro case obviously, but I provided information and evidence that it wasn’t functioning correctly. Unity have since agreed there was a bug and have attempted to fix it but actually asked me to confirm it was fixed because I guess they can’t even test it themselves.

Anyway, I know it’s not quite the same as your situation but I think you should at least report it. If they ignore it then so be it, but at least you’ve done your part in trying to get it fixed.