I have a problem with the one where the objective is to enter kateen forest from the tenate garden.
I had already done all of the npc quests in there and the next 2 areas so when i entered the forest the mission disappeared and now i have no clue where to go or what to do.
I thought the story missions were separate from the npc ones so you don’t do them when your in a region doing npc quests in a specific region where the story isn’t yet?
Also i just finished the mage tower level 5.
If you’ve already done all of Owl Burial Ground try heading up to the suburbs prior to the mage tower via escancia village. In particular go to the giant goddess statue and see if it will let you start the next leg.
You can skip large portions of the story by being the minimum level (usually about 15 below map level) and talking to the right npc. You may have inadvertently triggered that next stage.
There’s also a small gap in the story around that time to allow you to grind your next rank a bit.
Edit: just saw you’ve done mage tower 5. Aside from the next Klai story you should also be able to start the legwyn story arc on the orsha side which is minimum 120 i think.
No worries, you finished the quest. The quest line (for mage tower) literally ends there. It’s okay!
Where is the legwyn area o.O?
Also aha i did all the npc quests in those 2 areas before i even got to the mage tower.
Also did the left side with the farm areas.
Just to clarify, legwyn area begins from Starving Demon’s Way (121) all the way to Sanctuary (145). There are also 2 maps (120 Dvisia Peak / 123 Sunset Flag Forest) near the Kateen area. Note that those 2 have nothing to do with the Kateen quests.
But I think his Legwyn answer wasn’t really addressing your question. Your question was “how come the quest suddenly disappeared, did I miss anything?”
The answer, as I’ve said, is that the quest ends with you visiting Kateen Forest. Hope that resolves your query. 
I’d take starving demon way to alter way then head north to trigger the goddess statue then south to Genar then east to Manahas.
I’ve heard that you have to have been to Sicarius first but I’m not certain that’s true. I think it will let you pick up the story north of Fasika Plateau via Manahas.
I’ve also likely misspelled all these names.
Thanks.
Sorry i didnt explain it right >.> i suck at explanations lol
Also i never even noticed that entire path so i dont think i would have seen it if you didnt mention it ^.^
I wish they made the story missions more straight forward and clear so you dont get lost so easily x.x