Pls see also Post 1. and 8. of
https://sourceforge.net/projects/keepass/forums/forum/329221/topic/5506891/index/page/1
This is a copy of my post (8.) there:
WIN 7, 64 bit, Keepass 2.19
After several sync tests that ended in many many lost entries here is a description of what I did.
My target is to sync step by step several kdbx files to have 1 in the end with all entries.
1 Laptop. Local directory with original.kdbx.
USB stick. Create new: target.kdbx. Save. Closed Keepass (just because I thought may be...).
Opened target.kdbx. Opened original.kdbx. and checked:.
Verify that all the database settings of the two databases are identical (File->Database Settings). Particularly verify that "Use a recycle bin" is checked in both database and that the history settings are identical. If history is different, set both databases to match the settings of the database with the least restrictive rules. Save the databases...
Closed Keepass.
Checked the sizes:
original.kdbx 54KB
target.kdbx 3KB
Opened Keepass (target.kdbx).
Synced.
I have 2 identical copies now. (with lots of double empty groups).
original.kdbx 54KB
target.kdbx 54KB
Now I tried a second sync the same way with another file: original2.kdbx
Checked the sizes:
original2.kdbx 110KB
target.kdbx 54KB
Afterwards:
Just 2 of 24 groups were copied to target.kdbx.
1 entry lost in 1 group.
All older groups (origin was original.kdbx) are lost in target.kdbx.
original2.kdbx is a copy of target.kdbx. Most entries are lost.
original2.kdbx 29KB
target.kdbx 29KB
Duplicate of forum thread
https://sourceforge.net/projects/keepass/forums/forum/329221/topic/5506891