I just had the same thing happen to me. With my Sentinel. I completed the mission, deconstructing an artifact 336 Thrysian Chest piece. It shows I completed the mission, but there are no 336 artifact pieces available. I logged out, and back in, nothing. Frustrating.

Yes,, please stackable.

Summon him via Companions & Contacts (N) menu. He'll be under Followers -> Main Characters, and he'll be the only summon-able NPC on that list. This worked for me. Thanks

logging out and logging back in worked for me.

Thanks Kogul! Worked for me too!

I logged out as stated before, and the quest worked. I was able to disable the shield generator.

Yes, I'm sorry you are having that problem.

I am still not seeing the mission "crumbs" on any of my maps now. So I have to try to look all over the map to try to find what mission items. Also the Area Map, rarely presents itself on my HUD map. I have to toggle back and forth and now it is not even showing on my HUD map. I am really getting frustrated with this to the point of quitting the game and finding something else. I really love the game and have been a subscriber for over 5 years. Please fix the problems. thank you