Pieces disappearing from save file

Hi,

I am running:

Machine: Alienware Aurora R8, 32GB RAM, RTX2080Ti
OS: Win 10 Pro version 1903
Java 8 build 211
Vassal 3.2.17

The module in question is for Time of Crisis, v2.00. I am not the original author of the module, but I created this updated version recently.

Users report that after creating a new game, doing a few manipulations to pieces on the board, saving the game (.vsav), closing the game, and then loading the save game with or without restarting vassal, pieces in some of my At Start stacks on a public map, which were present when the game was saved, have disappeared. The pieces in question were not moved after creation of the game. Also, the disappearing pieces have no commands attached, apart from a command to print something to the chat window when they move.

In more detail, I have an At-Start Stack with 8 pieces, that looks like this:
Stack
– Type A
– Type A
– Type A
– Type A
– Type B
– Type B
– Type B
– Type B

The four Type A are all identical, apart from different images, and the four Type B are all identical, apart from different images. Type A and Type B share the same prototype, which prints a line to chat when moved. The only difference between Type A and Type B is that Type B has a Flip layer (two-sided piece) and A doesn’t.

What I find is that if I move all the Type B pieces from their starting location, without moving any of the Type A pieces, save the game, close, and reload, the Type A pieces are no longer present.

If any Type A pieces are moved before saving (even to simply change their stacking order), those do not vanish. Any unmoved Type A pieces do vanish, though.

Moving all Type A pieces and saving does not seem to make the Type B pieces disappear on reload.

I am pretty stumped, both as to why this would happen, and how to debug it further.

Any suggestions appreciated, thanks.

Dave