I've done some more research about this problem and tried the adb backup as described here [GUIDE] Full Phone Backup without Unlock or Root and then extract the data using this guide [GUIDE] How to extract, create or edit android adb backups.
Then I found out the backups of the non working apps contains no app data at all. For the working apps, the app data was included. This is the same issue as with Helium, but Helium uses the same way to make the backup as far as I understood.
My conclusion is that something must have happen to the app data when update was triggered, and therefore I guess there is no way to get it back.
Well the positive side of it, I lost my game progress in Candy Crush Saga, so at least I'm done with that. Not starting it all over again.
I have a Samsung Galaxy Tab 8.9 (GT-P7320) with Android version 4.0.4 (not rooted).
Some weeks ago, the device freeze during use, and I have to restart by holding down the power button. It took much longer time to start up than usual, therefore I tried another restart (during startup). I probably shouldn't have done this, because this seems to trigger some kind of updating and afterwards a lots of things seems to be back at factory default (icons on start screen, wallpaper etc).
But the data on the internal SD card storage was intact, and all my apps was still installed. But most of the apps was unable to start. It gives a message "Unfortunately, <app name> has stopped". I have found out that if I reinstall the app through Play Store, the app starts working again, but all the settings and data for the app is lost.
I have only so far done this with the apps with no important data or settings, and tries to find out if there is a way to make a backup of the app data before reinstalling the app. I have tried Helium, and it seems to back up the data, but when restoring it's still the same error message. If I try Helium on one of the apps I have reinstalled, it seems to work fine to restore these (incl app data).
I'm no expert on Android but could it be some kind of permission problems? It's very annoying that Android doesn't have a better solution to make backup of app data. Some apps store the app data on the SD card, for example Bad Piggies, and for this app, I copy the app data folder to my computer, reinstalled, and copy the app data back and everything works fine. But the problem is that most apps doesn't store the data on the SD card.
I understand that by rooting the device I will maybe get access to the app data folders, but rooting is not an option.
So my question is, is there another way to get my app data back?
I have read a little about the way Helium works to get access to the app data without root by using some developer features. Would it be possible to get access to the app data on my device, by connecting it to my computer and then use some kind of developer access?
I have also looked at Samsung Kies, but as far as I understand it's not possible to use this to make backup of app data.
I would be glad for any help regarding this issue, and still if there is no way to get the data back, I would like to know.