Does the feature exist anymore (or did it ever exist) to update saved games with changes made to a module expansion. Particularly with icons used when a character piece moves. I am not seeing anything called Updater in the tools of the editor in Vassal version 3.7.18.?
Try:
Tools…Refresh Counters to update an individual game that you’ve opened.
or in the Editor:
Tools…Refresh Predefined Setups to update all the setups in a module or the currently loaded extension.