How to replicate this bug: - Avoid researching physics until you have affinity level 2. - Research physics. - Go into unit upgrades and pick your updates for Rangers. - Congratulations, you just have a really cheap tier 2 unit at the price of tier 1! Have fun breaking the game. The same process can be repeated for any other unit type bar soldiers, if you can reach the affinity level for their upgrade without researching the unit. Rangers are the easiest to avoid until t2 is available, combat rovers is possible if you can live without thorium reactors and don't want Robotics. Might want to fix this for BERT if you haven't already. Hard to believe that this hasn't been squashed by now, game is so easy if I accidentially trigger this bug.