Sudden end - What am I doing wrong?

[gummybaer123]

Hello
I have been playing UFO AI for a while. One game I played until the game didn't move along any more (down the road after the battle in the canyon). No more to research. I found out, that  research on two bases leads to some mess up.
I played another game. Research on one base, harder difficulty. This time I got a fight in a bunker, but no canyon. Research on one base seemed to work better. Now, suddenly there was the todo sequence invasion and the game just ended. I checked again and found no reason for that (alien virus, whatever that is, only 3 %, happy earthlings) and there seems to be no way to do anything about it.
What can I do?
Oh, I have been playing 2.2.1, I will try 2.3, but probably that won't help.
Thanks.
Matthias

[Chriswriter90]

That may be the "end game" thing.

There's another todo sequence for the introduction of XVI.

[gummybaer123]

So what does that mean?
The aliens won, even though I have beaten them so far? (I know when researching the ammo for those particle guns, the scientist says, the aliens are far advanced and dangerous, but they say that all the time).
I haven't even been able to research psi and build crazy things with alien materials...
Matthias