Get the 1.04b patch off the Worthplaying server

More links on the official IL-2 Sturmovik page

IL-2 Sturmovik

Warning

The current version (1.04b) is not compatible with the previous versions of the game when playing via network. Both the server and client must have appropriate
versions of the game (1.04b) in order to connect. Track, training and intro files recorded with the previous version(s) will not playback correctly in the current version of the game.

Notes on the Patch Installation

The 1.04b patch may be installed over the previous versions 1.04 or over combined 1.04+1.04a.

======= Version 1.04b Changes =======

1. Fixed an issue with certain multiplayer host functions reverting to default whenever a new player joins.
2. Fixed inability to start engine in the air in COOP mode.
3. Fixed non-rotated propellers in COOP mode.
4. Fixed an Il-2 rear gunner bug in COOP mode.
5. Fixed an issue with bailing out in COOP mode.
6. Fixed periodical damage on airfield when player restarts (Dogfightmode).
7. Fixed the bug causing the following error message: "Mission loadingfailed: Mesh 3do/Buildings/Airdrome/HangarT1S1DMG_W/mono.sim not created."
8. AI planes now attack ships.
9. BI-1 control column now correctly mimics the direction of player'sinput.
10. Fixed the gear sound bug on PZL P11c.
11. Addressed climb and speed data for Il-2s and LaGGs. Fine-tuned maximal speeds at all altitudes for all planes.
12. Corrected engine power for MiG-3ud.
13. Corrected ground physics. Now even PZL P.11c will be able to turn easily on the ground.
14. Fixed bug with View Career Statistics, which caused the Aircraft Lost count to be increased by 1.
15. Corrected position of engine sound for P-39 and BI-1 (it is now behind the pilot).
16. Decreased level of airframe durability for PZL P.11c.

Note: Other updates and new aircraft will be available in patch/add-on 1.05.