I went accross a bug for 2 units, a mot. infantry and a medium tank that I was able to upgrade whereas I did not research those upgrades yet.
I had other mot. infantries and MTs but only those two units (that were part of a stack with other legit upgradable units - armored vehicules and light tanks) could possibly been upgraded.
Here are the screenshots:
So I took a chance, selected those units through "split stack" and upgraded them. The needed ressources have been taken out and the units went on upgrade for the needed time (approx 1h30).
But when I came back after the upgrade time, the upgrade was technically finished but the units were still level 1.
The bug here is that the game tells you you can upgrade the units and eventually let you spend the ressources needed. For an upgrade that actually doesn't exist and will not happen in the end.
I had other mot. infantries and MTs but only those two units (that were part of a stack with other legit upgradable units - armored vehicules and light tanks) could possibly been upgraded.
Here are the screenshots:
So I took a chance, selected those units through "split stack" and upgraded them. The needed ressources have been taken out and the units went on upgrade for the needed time (approx 1h30).
But when I came back after the upgrade time, the upgrade was technically finished but the units were still level 1.
The bug here is that the game tells you you can upgrade the units and eventually let you spend the ressources needed. For an upgrade that actually doesn't exist and will not happen in the end.