Vassal v3.6.3.
Example: The exact same property is used to set the condition for Global Property to disable this button when "true" in two GPIW buttons and a GKC button. The property is initially set “true”. Before a game is opened, all three buttons are disabled, as expected. If fact, the GPIW buttons were disabled even if before the disabling global property was added.
When a game is opened, the controlling GP is “true”. The GKC button is still disabled, as expected. However, the GPIW buttons are not. This is the problem.
Once the GP is set “false” (when all players seats are taken), the GKC button becomes enabled, as expected. The GPIW buttons also continue to be enabled.
Demonstrated in Liberté v1a08.
These are the relevant items in the module:
To demonstrate, start a game as blue, select 3 players when prompted. Notice that the GPIW buttons are now enabled, as shown below (but the hour glass will be greyed out, ie disabled):
Join 2 other sides (to do this as a solo player, press Alt+Shift+R). Once the 3rd seat is taken, the End Turn button will become active.