Alien Key decyphering

[Alazar]

I constantly run into a problem where I cant get this research done, because I dont get some researches for it even though I did all interrogations to point where I cant even interrogate anyone anymore. Also often I get duplicated info after interrogations.
All this places the game in a dead end, where you cant free any country from alien control.

Slapping a save file for dev to take a look. I interrogated to max all Sectoids, all MiB and all Hybrids.

[osd_daedalus]

Hi,
Just looked at your savefile (I had the same doubt some days ago, and asked in discord channel), and you still miss some crucial clues to unlock the alien decryption key.

Hint: continue exploring the hybrid arc...

Detailed (spoiler):

Spoiler:

looks like you miss a live human clone to capture (hybrid mission), and to discover something interesting in the secret hybrid clinic missions. Once you get both you can unlock the other alien infiltration methods in research. 

[Alazar]

Thanks for the hint, got the research done.