Lin lost and found

[Charlemagne]

Lin went missing a while after I recruited her. She was on the Frontier for a while then when I went to assign crew, no longer there or in the list.
It seems it is a common bug. I tried various suggested fixes and finally one worked. I post them here in case someone finds them useful.
1. Go back to Vectera, into the mine, mine something, come out. For some, she appears the way she was when you first recruited her, but in my case NOPE.
2. In console 'prid 5639' and then 'moveto player' (without quotes). If she's somewhere she will appear at your side, but I got errors about invalid references and invalid objects, meaning at the moment Lin did not exist anywhere in the game universe. NOPE.
3. Look for her at the Cydonia bar. NOPE.
4. Change ship back to the one you had at the time when she disappeared. In my case the Frontier. YES. She was standing there in the ship bay and reappeared in the list. I didn't assign her to anything, so she started walking towards Cydonia, presumably to the bar.

Various causes for this bug have been suggested. Apparently, she gets ghosted into the ship somehow so she isn't in the game anymore.

[Charlemagne]

OK Lin went missing again, and now nothing works. She seems to be gone for good. Pity, she's a level 3 outpost manager and besides a named character with dialogue and all that. RIP.
One can only hope that Bethesda is aware of this bug and will fix it. Maybe.

[Doombringer]

I had the problem with lin & heller disappearing.
I loaded a previous save where I still had them on the crew list, then loaded the game where they were missing and they were again on the crew list. (but not physically in the ship anywhere)
I then reassigned them to the base I was at and haven't had a problem since...