Index: java/com/l2jserver/gameserver/network/clientpackets/RequestAcquireSkill.java
===================================================================
--- java/com/l2jserver/gameserver/network/clientpackets/RequestAcquireSkill.java    (revision 417)
+++ java/com/l2jserver/gameserver/network/clientpackets/RequestAcquireSkill.java    (working copy)
@@ -94,7 +94,10 @@
        if (!Config.ALT_GAME_SKILL_LEARN)
            player.setSkillLearningClassId(player.getClassId());

-       if (player.getSkillLevel(_id) >= _level && _skillType != 3)
+       // If current skill lvl + 1 is not equal to the skill lvl you wanna learn (eg: You have Aggression lvl 3 and the packet sends info that
+       // you want to learn Aggression lvl 5, thus skipping lvl 4.) or the packet sends the same level or lower (eg: Aggression lvl 3 and the
+       // packet sends info that you want to learn Aggression level 3).
+       if (Math.max(player.getSkillLevel(_id), 0) + 1 != _level && _skillType != 3)
        {
            // already knows the skill with this level
            return;