swampwallaby-work@4308 has a couple of changes to display the correct error message if you try to load an invalid module.
Try repeatedly loading a non-zip file (say a .png file) and after the first time, the code drops through to AbstractLaunchAction:335 which displays a couple of non-existent error messages. Can you have a look at this bit?
I think I have sorted this out. 4308 combined with 4309 seems to work well.
Only valid module files can be opened or edited
Only valid extension files can be edited
Only valid save game files can be loaded
Improved error messages for load failures
Users are warned of a mismatch between the module name/version of a saved game and the current module with option to cancel load.
The earlier problem I reported seems have sorted itself out.
I also found and added bunch of missing I18N keys to VASSAL.properties, mostly Error.xxxx keys. There some I haven’t added as they are so esoteric, any sort of description is barely more understandable. Perhaps some of these could be combined into a single error message. I don’t think translations will be required for these.
Because they get closed quietly in the finally block anyway and if the launch catastrophically fails (and is reported sensibly), the first close() calls where failing and generating additional unneeded error dialogs.