Can't get useful data
You was working on your family tree. At some point Family Gem crashed.
You still see your tree in Trees list, but the tree doesn't open anymore, displaying only the message:
Can't get useful data.
To see the content of the tree file, make sure that Advanced tools is switched on.
Then go to Trees → ⋮ menu → Save ZIP backup and export the ZIP file somewhere on your device.
Inside this ZIP file you can find the tree.json file, which is an exact copy of the tree file used internally by Family Gem.
Probably you will observe that tree.json is a 0 byte, completely empty file.
This is the definitive proof that your tree data is lost.
We are very sorry for that.
The most notable reason of an empty tree file is that the app crashed exactly on the same moment of saving.
We are talking about a coincidence of thousandths of a second. It is rare, but it can happen, especially with a large tree.
Probably Trees → ⚙️ Settings → Auto save is switched on.
This means that the file is saved automatically immediately after each single modification on the tree.
This increase the probability that a crash occurs exactly during a saving.
At the moment there is no an automatic system to recover the broken tree file.
You could recover your broken tree in these cases:
- A ZIP backup of your tree has been exported before the crash.
Then you can re-import it with Trees →→ Recover a ZIP backup.
-
Your tree has been shared not before a month ago.
A shared tree is kept on the online server for one month, then it's automatically deleted.
You can find it following a link similar to https://www.familygem.app/share.php?tree=20251231120000. -
Your tree was exported as a GEDCOM file before the crash.
Then you can re-import it with Trees → - Last chance is to take advantage of the automatic Google backup.
Simply uninstall Family Gem and reinstall it from the Play Store or from an APK.
→ Recover a ZIP backup.We are working to fix this monumental problem, especially creating an automatic tree backup that can be easily copied back.