MissionResaver.exe creates invalid .msnbin after 6.107 update (Mission Editor: “Error reading mission file”)

[Corralandy120000]

Hi,

I’m working on my own external career mission generator for IL-2 Great Battles, and after the latest update I started having a consistent problem with MissionResaver.exe.

Game / setup

• IL-2 Great Battles version: 6.107

• Install path (Steam):
  D:\SteamLibrary\steamapps\common\IL-2 Sturmovik Battle of Stalingrad\

• Missions generated into:
  ...\data\Missions\Luftwaffe Career Generator\

My tool just creates standard text missions (.Mission + .eng), then calls MissionResaver.exe to generate .msnbin so the missions can be played in game.

The issue

1. The generator creates a mission file, for example:

   ...\data\Missions\Luftwaffe Career Generator\20251117_2104_Stalingrad_Intercept.Mission
   plus 20251117_2104_Stalingrad_Intercept.eng. etc.

2. At this point there is no .msnbin in the folder yet.

   • The .Mission file opens normally in the Mission Editor – no errors.

3. Then I run the official MissionResaver.exe from bin\resaver with the same arguments as in the stock batch file:

   MissionResaver.exe ^ -d "D:\SteamLibrary\steamapps\common\IL-2 Sturmovik Battle of Stalingrad\data" ^ -f "D:\SteamLibrary\steamapps\common\IL-2 Sturmovik Battle of Stalingrad\data\Missions\Luftwaffe Career Generator\20251117_2104_Stalingrad_Intercept.Mission"

   • No extra options (-t, -o, etc.).

   • MissionResaver.exe finishes successfully (exit code 0).

   • It prints:

     Loading ... 20251117_2104_Stalingrad_Intercept.Mission DONE

     Saving localisation data DONE

     Saving binary data DONE Saving .list DONE

   • It creates 20251117_2104_Stalingrad_Intercept.msnbin (and .list). etc.

4. From this moment on, when I try to open the mission in the Mission Editor, I get:

   Error reading mission file

   The mission cannot be opened in the editor anymore, and it also does not work in game.

5. If I manually delete only the .msnbin file and leave the .Mission and .eng in place:

   • The Mission Editor can open the mission again without any problem.

6. If I then use Tools → “Resave all missions in folder” inside the Mission Editor on the same folder:

   • The editor resaves the mission,

   • Generates its own .msnbin,

   • And after that the mission works fine both in the editor and in game.

So the text .Mission produced by my generator is valid.

 

Question

 

Is this a known issue with the current MissionResaver.exe (6.107)?

Has something changed in the .msnbin format or validation that affects external tools calling MissionResaver from the command line?

Is there an updated / recommended way to compile .msnbin for custom missions outside the editor?

The problem appears only when I use the command-line MissionResaver.exe – the .msnbin it creates now seems to be rejected by the current Mission Editor / game.

This started after the latest update: all resaver-related files (MissionResaver.exe, common.dll, math.dll, MissionManager.dll) in my IL-2 bin\resaver folder now have modification date 11 November 2025. Before that, the exact same generator + resaver workflow worked fine.

 

Thanks in advance for any ideas, suggestions or help. I really appreciate any pointers on this.

 

Andy

 

 

[No_85_Gramps]

Here is a link to the updated version of the MissionResaver: