A soldier can’t be upgraded past a single star until their unit (Engineer, Engineer II, Assault, Assault II, Assault III, etc…). I love the system now that I understand it, but it took a while for it all to make sense. I think that there is probably a better interface that could be designed for this. At the least until something better could be developed, when you link us to the unit that is required for upgrading the soldier just make it more clear with a popup or something. “You must play with this squad to upgrade your Engineer II past the current level.” Maybe even show a few screenshots of how to do it. I have overcome this obstacle personally, but some of my friends just won’t play because they can’t get past how much time it takes to navigate around upgrading between battles. The user experience is pretty complicated and almost requires a PHD in Gaijin to try to understand exactly HOW to upgrade everything. I have spent HUNDREDS of hours and dollars across many of your games. I love what you guys do.