Exporting backup fails

[Korsani]

Describe the bug
Exporting a backup leads to a 0b size file

To Reproduce
Steps to reproduce the behavior:

1. Make a backup
2. Export it to, say, Download directory
3. See error
4. See the file size: 0

Expected behavior
Exporting export a valid file

Screenshots

Smartphone (please complete the following information):

• Device: fairphone
• OS: android
• Version 15