Thanks, asheshouse... I tried to install it in BAT, but got a "null" error at loading a mission. I think I found the problem, at end of logfile :
[2019-05-07 22:00:37.804] dT: 0 at com.maddox.il2.objects.air.Aircraft.weaponsLoad(Aircraft.java:2435)
[2019-05-07 22:00:37.804] dT: 0 at com.maddox.il2.objects.air.Aircraft.load(Aircraft.java:2135)
[2019-05-07 22:00:37.804] dT: 0 at com.maddox.il2.game.Mission.loadAir(Mission.java:1288)
[2019-05-07 22:00:37.804] dT: 0 at com.maddox.il2.ai.Wing.load(Wing.java:144)
[2019-05-07 22:00:37.804] dT: 0 at com.maddox.il2.game.Mission.loadWings(Mission.java:1078)
[2019-05-07 22:00:37.804] dT: 0 at com.maddox.il2.game.Mission._load(Mission.java:653)
[2019-05-07 22:00:37.804] dT: 0 at com.maddox.il2.game.Mission.access$600(Mission.java:123)
[2019-05-07 22:00:37.804] dT: 0 at com.maddox.il2.game.Mission$BackgroundLoader.run(Mission.java:409)
[2019-05-07 22:00:37.804] dT: 0 at com.maddox.rts.BackgroundTask.doRun(BackgroundTask.java:155)
[2019-05-07 22:00:37.804] dT: 0 at com.maddox.il2.game.MainWin3D.loopApp(MainWin3D.java:108)
[2019-05-07 22:00:37.804] dT: 0 at com.maddox.il2.game.Main.exec(Main.java:422)
[2019-05-07 22:00:37.804] dT: 0 at com.maddox.il2.game.GameWin3D.main(GameWin3D.java:235)
[2019-05-07 22:00:38.771] dT: 0 WARNING: ****( Unexpected txr reload (tfNoCompress16Bit,tfCompressMajorAlpha): '3DO/Plane/Textures/propellor.tga'
[2019-05-07 22:00:40.214] dT: 0 null
[2019-05-07 22:00:40.214] dT: 0 java.lang.NullPointerException
[2019-05-07 22:00:40.214] dT: 0 at com.maddox.il2.game.order.OrdersTree.getSection(OrdersTree.java:627)
[2019-05-07 22:00:40.214] dT: 0 at com.maddox.il2.game.order.OrdersTree.missionLoaded(OrdersTree.java:567)
[2019-05-07 22:00:40.214] dT: 0 at com.maddox.il2.game.order.OrdersTree.missionLoaded(OrdersTree.java:531)
[2019-05-07 22:00:40.214] dT: 0 at com.maddox.il2.game.Mission._load(Mission.java:762)
[2019-05-07 22:00:40.214] dT: 0 at com.maddox.il2.game.Mission.access$600(Mission.java:123)
[2019-05-07 22:00:40.214] dT: 0 at com.maddox.il2.game.Mission$BackgroundLoader.run(Mission.java:409)
[2019-05-07 22:00:40.214] dT: 0 at com.maddox.rts.BackgroundTask.doRun(BackgroundTask.java:155)
[2019-05-07 22:00:40.214] dT: 0 at com.maddox.il2.game.MainWin3D.loopApp(MainWin3D.java:108)
[2019-05-07 22:00:40.214] dT: 0 at com.maddox.il2.game.Main.exec(Main.java:422)
[2019-05-07 22:00:40.214] dT: 0 at com.maddox.il2.game.GameWin3D.main(GameWin3D.java:235)
[7 mai 19 22:00:48] -------------- END log session -------------
Looks like a texture (propellor.tga) is missing...