I have previously reported an issue with the Britannia module. I have been trying to narrow down the issue and it seems to be a core VASSAL issue starting at version 3.5.4.
To reproduce it I need at least two .vlogs.
I start with a fresh 4 player game.
In the first I create a Roman unit in the Icelandic sea.
In the second I delete the Caledonian in the Orkneys.
When I replay these files one after the over the Caledonian is not deleted.
We are using the module version 2.4.1 but it also affects 2.4.
This does not seem to have caught anyone’s attention. Just to be clear I am claiming it is a bug in VASSAL > 3.5.3 not the Britannia module.
That said it does raise the question why it affects the Britannia module and not other modules. I may still be investigating that question, but I did manage to find a version where this was working in one and then broken in the next.
Or is there a different way of raising bug reports?
I am curious what the underlying issue was and perhaps any other impacted games were identified. I am sure it must have been something specific that Britannia was doing but I had a look and I could not see anything especially odd.
There was a change made in version 3.5.4 to streamline the process of loading a new log file over top of the existing game. This change was no longer clearing out the existing game state completely before loading the new log file. This was then interfering with the replay of the log. I am not exactly sure why (or why it didn’t cause bigger problems), I didn’t dig deeper once I realised the old state was not being cleared.
I’m wondering if this might also be the explanation for some other unexplained log related issues that have been cropping up.
Obviously our current work around is to use version 3.5.3. However in the previous game we just loaded the .vlog files with no pre-existing load. If everyone either does that, or plays live or perhaps like Twilight Struggle the module never deletes pieces may be they can miss it.
And as you say it may be that it has been spotted in other guises.