Very strange. I see that Minion is trying to match it to an AddOn in our database but for some reason isn't able to.
Code:
DEBUG 2016-12-16 10:08:43,498 [Thread-22] gg.minion.service.AddOnDetectionService:interrogateDirs(333): interrogating TOC: C:\Users\Megapix\Documents\Elder Scrolls Online\live\AddOns\LoreBooks\LoreBooks.txt
DEBUG 2016-12-16 10:08:43,500 [Thread-22] gg.minion.service.AddOnDetectionService:interrogateDirs(354): LoreBooks - TOC Version: 5.19
DEBUG 2016-12-16 10:08:43,503 [Thread-22] gg.minion.service.AddOnDetectionService:detectAddOn(268): No addons match LoreBooks
You should be able to install it again using Minion and it will show up under installed. It will only loose track of it if your minion.xml is removed.
I'll do some more investigating as to why this is happening to LoreBooks. Thanks for the heads up.