... and it does not show on the Research Report.
Tip 1 : I purchased Artillery III at T-2 and at this time, I had no supply left for upgrading any artillery SF.
Tip 2 : at T-1 and T, I upgraded my eligible SF to Artillery III without any problem : hence, this is just a display bug, not a functional one.
Tip 3 : did I mention that I love AT and Tom's GW ? But IMHO, the bug does not come from here. [:'(]
