Well, after you have the ingredients (root, potion, wisdom rune and spider leg) => when you return to him and speak, he should say: I see you have all, place them into the circle and summon. Then you click on the book.
I think, you've run into a linearity bug. I had all and still no acknowledgement from him. So, I started again - by following ALL steps in order.
Every time I took an item, I clicked on it and moved in my inventory - just to make sure, the game understands how far I am
1. Get Raan's blessing
2. Talk to instructor for the quest, get the key for the corridor leading to the library
3. Library => read ALL books (mycology, 2 imp guides, summoning book)
4. Talk to the specimen organizer Belehram, she tells you where the ingredients are. Listen and talk to the students thre, ranting about the mage
5. pay 500 gp to junkie Dolehar to access the specimen room, kill/take spider leg
6. go to Ansukar => tells you about runes
7. go to rune room, get wisdom rune (north wall, 2nd last rune)
8. Go to Nixfix in the tunnels - learn about the mushroom, get it, trade it for root
9. Enter lab - talk to mage - DON'T kill him yet! Exit conversation. Talk to female student and then she will go to lure him away. Get golden key, opene small cupboard - get 2nd key there - open large cupboard => potion. As an alternative => you can kill the mage - but exit convo first and then start again. he will drop this key.
10. then I went to the instructor - and I saw XP fluttering up as I entered the small room. Went to him => he said: you've got all.
Some German gamers were successfull in placing all items on the ground and then taking them up one by one - before they went to the instructor for the last time. So, click on them to take, them and move them in your inventory... maybe this helps.
9.
