Many of my spells/abilities have somehow gotten jumbled up. This is happening on patch 1.0.132.
For example, Oath of Desecration now weakens me, Air Shield instead casts Earth Shield, Fireball casts Flare, Summon Undead Decapitator summons an ice elemental, Ice Shard casts Piercing Ice Shard, Piercing Ice Shard casts Ice Shard and Ice Wall casts "Immediate Crash to Desktop."
Unfortunately, this is not unique to one save game. I have tried loading multiple saves across multiple characters and they are all the same: jumbled up spells followed by a crash.
I will try reinstalling the game.