no, the one that allows you to craft legendaries using disassembled items. ah sorry i posted the wrong name. I meant this one. 
Edit: I still haven't found it.
Edit 2: by the way I kind of noticed that every time i do Ice raid then go to Fire raid the Autosave suddenly turns ON even though I already turned it off. Idk if it is also the same with the other people.
The dusty crafting book fpr the legendary item can be found in a chest in the fire raid area, which only appears after you won a solo fire raid. (Solo raids unlock after you've won enough fire raids with the raider group)
The auto-save is disabled during the fire and ice raids, as it is not intended that a save is created during the on-going raid events. It's not intended that the auto-saves is turned ON if it wasn't active before the raid, but maybe something went wrong. I'll take a look at it.
