After Killing the Sewers Act 2 Boss On Nightmare, The Character Froze Solid. This in turn Required me to make a New Game to fix but once I returned to kill him again I lost out on the BOOK of Skill. Now my Character is FOREVER nerfed by 1 Skill point. This needs Addressing Fast. There should be a way to get book if this happens something like with cube in act 3 after a rush.
Create a normal game, then leave and create a nightmare game again.
In classic diablo 2, this would correct the bug, making radQ available again so you could collect your book.
Also, you can join a public act 1 game, if you can find one, and go to act 2, then kill raddy there, which should get you your book.