The function number: N/A
The complete error text: N/A
The window affected: Naval Org
What you were doing at the time: Loaded up 1.92 game on the 1.94 patch. All sub-fleets in the fleets are moved up under the main fleet. So sub-fleet hierarchy isn't saved.
See screenshot for how 1st fleet was organized, then compare to how it looks in DB now
Conventional or TN start: Conventional
Random or Real Stars: Random
Is your decimal separator a comma? no
Is the bug is easy to reproduce, intermittent or a one-off? easy