[Update: This issue is fixed in Vassal 3.7.25 - bug fix ref 14902]
There is an issue introduced in Vassal 3.7.23 (released 8th June 2026) that will affect modules with customised user preferences that can be set via the module itself (e.g. from a Toolbar Button) or that use preference properties to store local data. The effect is minor - in general, a user’s preference may be overridden when another player changes their preference during a game. In some modules, the wrong player name will be reported for actions in the chat log.
A fix has been developed and, all being well, will be included in the next release of Vassal. Meanwhile, it you are affected, please revert to Vassal 3.7.22 which you may download from this page.
Examples of affected modules are recent versions of the following:
Commands & Colors: Napoleonics
Sekigahara: The Unification of Japan
Apologies for any inconvenience caused.