Hello,
Been playing since 2.11. Liking so far, guess it seems somewhat longwar-inspired (xcom2012 mod).
Few problems I've encountered so far:
1. I'm almost certain there's some sort of bug with biodrones. Since it requires researching a live one for certain important techs, I've tried stunning a biodrone on land terror maps. The interesting part though - it's not possible. Stunning them just generates a "corpse" object and doesn't trigger the explosion but that's it. Neither the tazers or thermal shok stun them properly. In fact, I don't remember actually how it was in TFTD vanilla either.
Logically, I assumed I need to get the ufopaedia entry from a "medic" alien, but that didn't unlock anything either.
Then I've dug into the research.rul and tried changing the "biodrone_terrorist" to just "biodrone" - and that fixes the problem (if there's one), the "medic" random biodrone entry will unlock corresponding techs. However it doesn't seem logical to me that you need to basically re-roll the medics until you get the biodrone.
So it's either a bug in being unable to stun them / depending on a live one when you can't get a live one. Or third - there's a secret way to obtain a "live" terrorist which I haven't found yet, even 1 game year later.
2. Alien Barge / Alien military base assault (land 2 stage mission) are missing battlescape music so they just play whatever music was playing just before the mission.
3. Again Alien Barge (Naga race) - I recall there was a Naga spawned outside of the Barge, bottom-left corner, basically in the air. 4th or 5th level. Lucky, there's a window to see this area, but could be annoying otherwise.
P.S.:
Are the "downed ufo crash site" useful somehow (except the free points opportunity) after the initial research? Inert Elerium / Flight records do not seem to have any dependencies either.
Can they be safely ignored just as mutant village missions, if you don't need extra points?
Update:
v.2.13 now has introduced a new crash when loading savegames (occured on large ship / base defense multiple times)
[FATAL] A fatal error has occurred: Corrupt state: Unknown original UFO destination.
Can provide saves if needed.