What program to use? HELP

When I try to open the Vassal 40k program it says
"To open this file, Windows needs to know what program created it. Windows can go online to look it up automatically, or you can manually select from a list of programs on your computer

What do you want to do?" :open_mouth:

I have no idea what to do. I tried the choice for looking it up online but it cant find anything. :frowning:
So what program should i open it with manually or what?

Thanks for reading, please help me ASAP. :exclamation:

Hey sorry bout this post but i just figured it out lol…you dont need to open the file its just used to open the module on vassal program. :laughing: :unamused: