Can't have Sentry Array and Science Nexus in the same system ??

[EXCAT]

Ver 2.7.2, no mods

In the attached game, there is on-going construction of 2 megastructure sites in Zorrikan black hole system.

Once Sentry Array site finishes, Science Nexus site building disappears, no reason given.

The planetary body around which it was being constructed is still there,
but I cannot restarted building it in the same system again.

Is it a bug, or there is some logic in there?

Note that I have Architectural Renaissance and Master Builders, so I can do 3 megastructures at once.
(3rd one is also in process of being constructed, in Terminal Egress)

 

[hart30]

There only can exist one megastructure per System. If you start the construction of 2 megastructures at once in the same System with construction ships, as soon as one construction ship is done, the other one stops and refunds ur spent ressources, because then the condition of no existing megastructure is not given anymore.
Not a bug.

 

[CrazyJ]

there are a few exceptions like being able to build a megastructure in a system with a ruined one and then repair the ruined mega. i've used this to get two science nexii in one system. if you are running gigastructural engineering all bets are off though, as there doesn't seem to be any limit to how many gigastructures you canadd to one system, well aside from the ones that consume the entire system.