HoMM3 HD is a mod (add-on) for the game Heroes of Might and Magic 3.

Update 3.25 -> 3.26 (12/23/2012), HD+

In the original, the Elementalist was overlooked, and wasn't specified as a mage when leveling up, which caused him to gain Wisdom at level 6 and Magic at level 4, while all other mages gain both at level 3. In HD+, this has been fixed, so Elementalists level up differently.

At least this fix could have been mentioned. And specifically. Not in general terms :). And how many more of these undisclosed minor bugs that have been fixed will appear?... Well, the fact that offline players used HD+ is, of course, their own fault. At least there is enough information about the fixed issues so that they don't use it offline.
And, if I remember correctly, the skill tree for Elementalists was also messed up in 2.98, or is it such a variable bug that it appears when it wants to. The skill tree also sometimes got messed up after loading a save.