Basically what ivandogovich said; it prereqs into Reticulan Power Systems. While that unlocks Power Tools, you can get that another way. The real issue is it's a hard requirement for Magnetic Containment Field, which is in turn a hard requirement for Plasma Weapons, Tesla Coils, and...Higher Studies (and through that, Mars). Which means the game is unwinnable.
The only source for Mechtoid corpse, other than a dead Mechtoid, is govt/Reticulan Files. But that needs Fusing Human and Reticulan Tech...which requires Reticulan Power Systems. So if you research Contacts:Reticulans prior to getting a Mechtoid Corpse (which I did), your game is done. This probably doesn't pop up real often because Contacts requires the Reticulan Elder, which is only on Mechtoid missions. But I stunned all of them. Cattle Prods worked better than any guns I had at the time with that armor.
Because I like to provide solutions when I see stuff, here's a few candidates:
1) Add the reticulan missions back into giftsOfBlood_SwayRets (you probably want to remove the limitation on Family Ties there, too, else the same problem will crop up if you research C:R and FT prior to getting your corpse, and currently I can't see any "giftsOfBlood" that is active in that case).
2) Remove the corpse requirement from Reticulan Power Systems (not great from a flavor perspective)
3) Create a 0-cost Mechtoid tech that's unlocked by live or dead Mechtoid research, use that as the dependency into Power Systems instead
4) Move the Reticulan Files manufacturing back to Contacts: Reticulans - you already have to get the live-captured Elder to get that anyway, so it probably wouldn't hurt.
