I have the Unstable Plasma blueprint and it's pinned as a side quest. I have 50+ oxygen and a metal plate crafted. Both requirements are now checked and all that's left is to craft it. I clicked on an empty tile in my inventory and Unstable Plasma (easy to recognize because it's green) isn't listed as one of my choices. I've flipped back and forth in the list of things I can craft, which isn't but 2.5 pages, and it's not listed. What should I do? Thanks!

A bit late for a response, but maybe this helps you: pinned formulas are like normal missions, they can have the problem that they must sometimes be re-activated in order to conclude. This happens when you move, use the teleporter or warp sequence, when you must use portable items, or if you reload the game.
Go in your log, chose another mission and then chose again the pinned formula mission. Assumed that you have done everything for the mission, it should now conclude and you will be able to craft your item.

Thank you for trying to help me. I disabled the pinned formula, picked something else, and then re-pinned the formula again. It's not seeming to help. Perhaps I'm supposed to talk to another alien and relearn about it? I'll try again right now.