This module. Battles of Napoleon: Volume I – EYLAU 1807 - Module Library - Vassal
Please state what module you’re having a problem with and provide a link to the module page where you found it.
I just downloaded this and it seems to run fine under Vassal 3.7.18 on Win11Pro. Downloaded it, clicked on it and went as far as starting a solo game, with no problems.
As a humorous aside, are the placenames on the map real or made up? Preussisch Eylau is obviously real, but some of the others seem laughable to a person fluent in German. Schloditten, Schmoditten, Melohnkeim, Kuschitten, Freiheit…ad nauseam.
Kuschitten? Really? Cowshit? 
These put the old, made-up, pseudo-German names from Avalon Hill to humorous shame. OTOH, I’ve been wrong about such assumptions before.
Ok. Describe how you tried to open the module and what the exact error message was.
. I downloaded everything on phone after this transfer on pc I start vassal on win10. Click open file it’s open folder with mod I try to start all scenarios but everywhere was error that it’s invalid mod for vassal.
пн, 10 нояб. 2025 г., 17:27 Joel Uckelman via Vassal <noreply@forum.vassalengine.org>:
So, what was the exact error message? Please quote it.
пн, 10 нояб. 2025 г., 17:53 Joel Uckelman via Vassal <noreply@forum.vassalengine.org>:
You’re trying to open a saved game as a module. Open the module instead. The file you should be opening is the .vmod, not any .vsav. You open .vsav files from the Player once their corresponding module is already open.
Ah!, it seems like you’ve unpacked the module Eylau_v_1_1.vmod and are trying to open the embedded save file Davout's Attack update 1.vsav.
What you need to do, is to locate the module file Eylau_v_1_1.vmod in your Desktop folder, and then double-click it to open it in Vassal.
If that fails, and instead unpacks the module or shows the content of the module file, then you should right-click the file Eylau_v_1_1.vmod and select Open with… and find and select the Vassal application. If prompted, you should let Windows associate .vmod files with the Vassal application.
If you cannot find the Eylau_v_1_1.vmod file - but you instead have a folder named like that, then you should remove that folder and re-download the module from the module library.
BTW, you do know you can select (highlight) text in an error dialog - like then one in your screenshot - press Ctrl-C to copy it, and then paste it into a message with Ctrl-V.
You may want to take a look at Joel Toppen’s VASSAL tutorial video - not so much about loading modules as how to use Vassal. This video may also be helpful.
An old video is this one - mostly for the historically minded 
We should probably make a separate Documentation page with a bunch of videos in it to help people getting up and running with Vassal.
Yours,
Christian
Ok I understand. Thank you for your help.
пн, 10 нояб. 2025 г., 19:20 Christian Holm Christensen via Vassal <noreply@forum.vassalengine.org>: