ArrayIndexOutOfBoundsException at startup after adding weight manually

[miedlarminprog]

Describe the bug
A clear and concise description of what the bug is.
I entered a weight manually and left all values unchanged - I only changed the weight and entered an comment. After saving this entry the app crashed, and thee attached exception appears when starting the app.

To Reproduce
Steps to reproduce the behavior:

Perhaps like described above. I can't reproduce, because I fear losing my database when I reinstall.

The error occurs on each app start. So I can't reproduce adding a weight entry manually

Reproduced with latest dev version:
See log

Expected behavior
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No exception

Additional context
Add any other context about the problem here.

Btw: can i backup the db somehow? Where is it?
log.txt

Debug log
Attach a debug log (see Settings -> About -> Save debug log to file) that is captured while reproducing the issue.