In mission number 4 i built three libraries big enough to attract warlocks... All creatures needs are satisfied, i tried building them on a quiet place, deleted libraries and leave one and still no warlocks... Any info on that?

All you need to summon warlocks is a 3x3 library. If you do indeed have that, is it possible warlocks aren't coming through the portal because you've already reached your creature summon limit?

IIRC, correctly, mission number 4 is Flowerhat and on that map, you have a summon creature limit of 20. If you already have 20 creatures, it's time to throw some of those flies and beetles out of your dungeon to make room for warlocks

Don't wait too long before building a library though - it should be one of your first rooms and if you're not quick enough in building one the enemy keeper might claim all of the warlocks.

Oops, thanks for pointing out that oversight. Post edited