The Data Slates say they need to be decrypted in the workshop, but I don't see an option for that. Is an there a 'Alien Encryption' research of some sort?
They are treated as manafuacture, so you must "produce" one decrypted from one regular.
Also on the other hand, I've reached the full ivasion part, and have some thoughts to share:
First of all I'd suggest making Interceptors easier to obtain. Before i've managed to get one, I had to (ahem. spoiler alert):
1. Find landed UFO, which is hard as hell.
2. Kill an alien and bisect it.
3. Research Alien Biology.
4. Research Alien Containement.
5. Construct Alien Containement.
6. Find another landed UFO.
7. Capture one alive and interrogate it.
8. Get promotion.
9. Research Migs (two times).
10. Curse them, because they couldn't catch anything before runing out of fuel.
11. Research Interceptors.
12. Wait 13 days to produce one.
So after all this time I've lost UK and Australia and got two Alien Base missions. I'd suggest giving any means to counteract full scale invasion before obtaining them. And maybe reduce production time (after all they all made from human tech, so I like to think they are rather assembled than made from scratch)
Second of all I don't know what to do with money right now. Before the invasion i had a 100 millions (and even without Wałęsa!) So I just built myself few bases. And then I sold all redundant items...
Don't know if this is possible, but could you make that we revert to original rank names after third promotion? For immersion reason i've changed it in ruleset, since XCOM is now military organization.
Also small note on one bug (sorry for wrong topic): EXALT is still giving me outpost even after their termination.
Still big fan of the mod.