Viktor Upgrade Bug [Gameplay] Patch 5.15
When playing as Viktor, I bought 2 Hexcore upgrades at one time. If Viktor's E (not sure about his other spells) is double clicked to upgrade, two upgrade stacks will be used. This allows for only two upgrades total, instead of the four usually obtained from upgrading all three abilities.
I first found the bug in a normal game, then went into an ARAM game to duplicate it. If you are actually able to upgrade abilities twice, new to me. Thanks.