Data loss after updates

Question

Level 1

90 points

Data loss after updates

Just a heads up for anybody with an app in the store that saves any kind of data to its documents directory. My first update was posted to the store today, and I have had a few users report that their data is lost after an update. I know that this does not always happen, as I was able to update the app on my personal phone (using the App Store app on the phone) without losing data, but at least one user followed the exact same process and did lose their data.

Posted on Jul 28, 2008 6:37 PM

Reply

Answer 1

Jul 28, 2008 7:17 PM in response to admanimal

Yep, I've had some users report the same issue. It seems to me to be similar to the issue of applications not getting installed correctly and quitting when user launches them.

If users make a backup of their backup, then they can restore the backup's backup and try updating again.

Backups are located in ~/Library/ApplicationSupport/mobilesync on the Mac. I dunno about Windows.

Reply

Answer 2

Jul 29, 2008 2:24 AM in response to admanimal

yikes.

Reply

Answer 3

chrisbw

Level 1

0 points

Jul 29, 2008 4:19 AM in response to admanimal

I am experiencing the same thing right now. My first update went live yesterday, and I've already received e-mails from customers who have lost their data. This is not good.

Reply

Answer 4

chrisbw

Level 1

0 points

Jul 31, 2008 4:58 AM in response to admanimal

Is anyone else still seeing this happen with their app? I've spoken to another developer who is reporting his NSUserDefaults preferences disappeared after he downloaded an update to his own app from the App Store.

I'm continuing to get user reports of this, though not all users experience it, and I can't think of any way to simulate this myself to try and figure out what conditions most likely cause it.

Reply

Answer 5

Jul 31, 2008 5:11 AM in response to chrisbw

Yes, it is still happening. I had two reports yesterday. Apple just released iTunes 7.7.1. Maybe it helps the situation.

Reply

Answer 6

admanimal Author

Level 1

90 points

Jul 31, 2008 5:20 AM in response to Mark Krenek

Most of the reports I got were from users who had updated using the App Store app on their devices, so an iTunes update isn't going to help that.

Reply

Answer 7

Jul 31, 2008 5:23 AM in response to admanimal

My users updated via iTunes. BTW, one user was able to get their data back this way...

I restored my iPod using a backup made before I downloaded your update. Then I decided to download it again on my iPod rather than using iTunes on my computer as I had the first time. It WORKED and I didn't lose my data this time.

Reply

Answer 8

chrisbw

Level 1

0 points

Jul 31, 2008 5:43 AM in response to Mark Krenek

Thanks for the sort-of workaround, though it's not a pleasant one, and a bit time consuming.

I guess the majority of the iPhone/iPod touch apps are stateless, thus this isn't a huge deal for them, however my app is completely based around the users entering and managing data on their device, so this is a *catastrophic data loss* bug for me, it's making me look bad, and it's eroding my users trust.

Reply

Answer 9

admanimal Author

Level 1

90 points

Jul 31, 2008 7:25 AM in response to chrisbw

Same situation for me. I'm planning to implement my own web-based backup/restore system so I don't have to worry about it anymore.

Reply

Answer 10

chrisbw

Level 1

0 points

Jul 31, 2008 7:28 AM in response to admanimal

I was thinking of doing the same, but didn't want to open up the whole world of complexity/privacy issues that would bring. It'd be nice if it just worked.

Reply

Answer 11

Aug 5, 2008 6:43 AM in response to admanimal

How about a bonjour based backup system with open hooks so any developer that wants to connect into it can broadcast for the bonjour backup system and send and receive files to it. One desktop app for all users this way instead of dozens.

Reply

Answer 12

chrisbw

Level 1

0 points

Aug 5, 2008 6:47 AM in response to Harland Macia

I'm seriously hoping this 2.0.1 update solves the issue.

Reply

Answer 13

chataka

Level 1

13 points

Aug 16, 2008 6:21 PM in response to chrisbw

Does anybody know if this problem has been fixed?

I am not sure what OS version it was, but one of my customers lost his entire data when he updated my app ...

Reply

Answer 14

Aug 16, 2008 6:58 PM in response to chataka

To those devs who were experiencing this problem, how was the reportedly lost data stored? Was this stored in NSUserDefaults, or as a SQL file? Anything stored in NSUserDefaults should IMO be considered disposable.

Doug

Reply

Answer 15

Aug 16, 2008 7:10 PM in response to Doug Dawson

My app's data is stored in its sandboxed documents folder, not using NSUserDefaults. I've had no reports of this problem in a while, but I have not released an app update in a while either, so there's not any correlation I can really make.

Reply