I've just tested,and the file downloads fine.
I'm not sure what is going on, so let's go through this step by step, and see if we can identify where it goes astray
1. Download the VASSAL engine that suits your operating system
vassalengine.org/download.html
2. Open VASSAL 3.7.8 .. check that VASSAL engine runs. You will have a Window called VASSAL 3.7.8 and an empty Module Library.
3. Download the Tricorne module v1.4 (or latest)
vassalengine.org/wiki/Module:Commands_%2..._American_Revolution
4. In VASSAL, File-Open Module and select the file named Tricone1.4. This file will open and then appear in your Module Library list.
5. Opening module will ask for a User ID and password entry (and confirm). Enter a user ID, any you like, and a password. The password is actually the key ID as a player, so it is a good idea to be consistent with that naming. Then select Next
6. You get 3 options, play offline, look for game online or load a game. For this purpose, choose the top option, game offline. Select Next
7. From the drop down list, select New Scenario for a blank map, or one of the pre-defined setups for an existing scenario. Select Next
8. Choose a role,. When creating scenarios, choose Observer. Select Finish
Let me know how this goes, and where it goes wrong and I'll see what else I can advise.
