Sewer Warded Doorway - not Umberlee

[Stolcor]

The book to progress the warded doorway quest does nothing once you get to it.

Also, on the first visit after a reset, certain doors blocking that book start unlocked and only lock after you get in, allowing you to bypass the puzzle completely.

N.B. The book for the Umberlee door did work. I haven't taken the next step yet, so we'll see.