Il 2 FB.exe crash

[4ent]

ok - OS.....Windows XP
last 6 month no hardware changes,no drivers changes
IL2 1946 v4.09mod AAA UI v1.1 + bunch of mods.My configuration was functionally , I played about ten campaigns (modded and unmodded) in various stages no problem,after 4 hours of playing I switched campaign from VVS to USAAF and crash.Started again change another campaign and crash.Sometimes I can play 2-3 missions in row and than crash sometimes crash immediately when load first.