I've found a bug where you can "lose" scientists in a base. To reproduce:
1. Begin research of an alien artifact
2. Go to Buy/Sell and sell that artifact so you have 0 in your base
3. Return to the research screen. The artifact has moved to the "Unresearchable Items" section, but the scientists assigned to it have vanished. E.g. if I have assigned 10/10 scientists to that artifact, I now have zero unassigned scientists and zero scientists assigned to any work. However, the other screens will still show that I have 10 scientists employed in that base.
I poked around in the code a bit and got some idea of what's happening, though I didn't get as far as fixing it. It seems that the scientists are still assigned to the artifact, but they aren't displayed because unresearchable items aren't supposed to have scientists assigned to them. Whether they continue to make progress, I don't know.
If I repurchase the artifact, it moves back to the upper part of the research list and the scientists remain assigned to it -- so you can get your scientists back.
I'm seeing this with the latest master as of this morning (5d2b5fc8).
