The situation I describe below is not necessarily a bug, but it is unexpected behaviour.
I am using Vassal 3.2.16, on a Windows 10 laptop. I encountered this issue in my own module (Messina), running custom code, and initially thought it was a bug I had introduced, but the same thing happens with GMT’s A Distant Plain (ADP), module version 2.0.
- Open a new game. In ADP, this is done by choosing File, Scenario, New.
- Without saving the game as a vsav file, start logging by selecting Begin Logfile from the File menu, and name the logfile Test.vlog.
- Drag some pieces around. (In A Distant Plain, I dragged a couple of Coalition bases from the Available Forces onto the main map).
- Stop logging by choosing End Logfile from the File menu.
- Close the game without saving it.
- Start a new game as in step 1.
- Choose Load Continuation, and select the logfile created in Step 2.
- Step through the actions performed in Step 3. The actions are announced in the chat window, but the pieces are not moved on the map. (Similarly, clicking the undo icon produces an announcement in the chat window that the move is being undone, but there is no visible change.)
- After all the actions have been stepped through, a dialog pops up saying the logfile has been finished, and offering to start a new one, but the game position is the same as if the logfile has not been run at all.
Repeat the exercise, but change Step 1, so that you save the game with a name, such as Test.vsav. Change Step 6 so that Test,vsav is loaded, instead of a new game. Now advancing through the logfile works as expected, with movement of the game pieces matching the reports in the chat window.
The problem only occurs with generic, new games. If, instead of choosing a New blank scenario in ADP, a specific scenario is chosen, such as the Short Scenario, then recording and later running a logfile works as expected - the same as if the game has been saved as a vsav file.
Perhaps you never expected logfiles to be run on unnamed, unsaved, generic games, but if the starting setup is the same each time, built from At Start Stacks, users and mod designers may expect that the sequence of moves in the logfile should be equally applicable to apparently identical starting positions. At any rate, I would have thought that the moves should not be reported in the chat window if, in fact, they cannot be completed.
If logfiles are only supposed to be recorded on games that have been saved with a specific name, then that Save process should probably be incorporated into the Begin Logfile dialog, and the user should be prevented from recording a logfile that will not be usable.
(On a side note, the Begin Logfile dialog does not give any indication as to what file extension is expected. If no file extension is provided, the appropriate one is added at the time the file is created, but it might be kinder to users to indicate the appropriate extension before they type the filename.)