Science Nexus tech not showing up

[DKnG14]

I have:
Cybrex precursor finished
Ring segment repaired
Mega-engineering researched (obviously)
Master Builders & Galactic Wonders
Ruined, not repaired Science Nexus within my borders

Still I can't get the Science Nexus tech to show up I bad want to have two Nexus

In fact no mega techs are showing up like Strategic Center or Sentry Array. The only three present are those from Galactic Wonders (ring, sphere, decompressor).

Is it beacuse I don't have Citadel & Battleship techs?
Or is it because I havn't finished enough high tier techs?

 

[koIdo27]

Or is it because I havn't finished enough high tier techs?

This is the reason. The megastructures are all tier 5 techs, so you need to have researched at least 6 tier 4 techs for them to appear. Normally you would need them to get mega-engineering in the first place, but since you got it ahead of time from the cybrex this can happen.

 

[DKnG14]

Things like Quantum Catapult or Ascension Theory (which, according to Wiki are both tier 5) are showing up though...

 

[Ishyro]

Quantum is 3, ascension theory is 4, and each science field (physics, society and engineering) are separated.