There’s no need to install Java on Windows (or MacOS). The packages we release come bundled with their own Java and won’t use anything you install separately.
There is seldom any reason to uninstall and reinstall Vassal. If Vassal starts, it is unlikely you’re having a problem which reinstalling will remedy.
Would probably be very helpful to read some of the how to tutorials online or watch some of the how to videos on YouTube detailing how to install Vassal and then how to load a module in it and get online and play a game against a live opponent or via play by email. It sounds like maybe you are double clicking on the modules you downloaded and that isn’t working because Vassal isn’t installed yet or not installed properly at least. Once Vassal is installed then you should open up Vassal itself and only then load a module up from inside Vassal, not by double clicking the module in your download folder and hoping it launches the app and opens up.
There isn’t anything you should click on that says “Open File” when you’re opening a module. There is no “Open File” in the File menu of the Module Manager, which is the window that opens when you start Vassal.
You open modules from inside Vassal. You need to run Vassal first, then go to its File menu. There you will find “Open Module”, which opens modules.
Everything you’ve said above suggests that you are in the file manager trying to open module files, not in the Vassal application where you ought to be.
If you showed us screenshots of what you’re seeing, we would have a better chance of helping you.
OK… don’t ask me how I did it, but I downloaded the Omaha Beach Mod and I appear to playing the game. You telling me that I was downloading it incorrectly made look around and try things while watching the video about Vassal on You Tube. Somehow I got it on my Mod page. I feel more confident if I can do it again.
Thanks for your Patience.