Recently Returned to Stellaris; A Bit Confused

[bobgrey1997]

During the Steam Winter Sale, I was able to purchase most of the DLC I was wanting, including Megacorp and Apocalypse. I've had Utopia for some time and have always based my playthroughs around the idea of building the various Megastructures, especially Ring Worlds.
The other day, I decided to go onto the Workshop and ensure any mods I am used to using are up to date and don't cause conflicts, as well as find any new mods that are made with these new DLC in mind.
On my most recent playthrough, I have expanded to sizable empire taking up nearly a 5th of the galaxy (1000 star sized) and have started building megastructures, both from the vanilla game and mods.
All was well until I decided to build a Ring World.
Both the normal Ring World, and my own "Fully Habitable" Ring World seem to be impossible to build due to some rather strange behavior...
Whenever I try to place one in a normal system, I always get the "Can not be built in system with habitable worlds", even if the system is nothing but a field of rocks surrounding a star.
I have found a mod that removes such placement limits, but when using it, all I get is "Cannot be built in binary or trinary systems", even if it is just a normal system.
I'm curious; has anyone else experienced these strange errors?

Another thing I'm a bit confused about is the Megacorp DLC' "Corporate" Planetary tab. If I set my empire to Corporate, I can't access the tab at all with the error "Corporate actions can not be taken on this planet". If I set as any other empire, the tab is fully accessible, but nothing is in it.
What is the purpose of this tab and how is it used?

I have not played the game for some time and have never played with these new DLC, so I am a bit confused.
Thank you for any information and/or advice.

 

[sillyrobot]

For the ringworld, verify the system doesn't have any mining or research stations present -- including around the star. I had similarly unhelpful error messages a while back and that was the cause.

 

[bobgrey1997]

Well, after a couple hours of trying to build one in each system in my massive empire, I decided to find a completely new, unsurveyed system, then survey and claim it (build outpost Starbase), but I still got the binary error even though the system was a normal single-star system...
During my trials with the rest of my systems, I started noticing that all of them had mining and/or research stations, which lead me to try colonizing a whole new system specifically for this purpose.

 

[sillyrobot]

Here's the requirement blocks from ringworlds:

Spoiler

resources = {
category = megastructures
cost = {
alloys = 5000
influence = 300
}
upkeep = {
energy = 5
}
}

possible = {
exists = starbase
custom_tooltip = {
fail_text = "requires_inside_border"
is_inside_border = from
}
custom_tooltip = {
fail_text = "requires_surveyed_system"
NOT = {
any_system_planet = {
is_surveyed = {
who = prev.from
status = no
}
}
}
}
custom_tooltip = {
fail_text = "requires_no_habitable_planets"
NOT = {
any_system_planet = {
colonizeable_planet = yes
}
}
}
custom_tooltip = {
fail_text = "requires_no_black_hole"
NOT = { is_star_class = sc_black_hole }
}
custom_tooltip = {
fail_text = "requires_no_binary_trinary"
NOR = {
is_star_class = sc_binary_1
is_star_class = sc_binary_2
is_star_class = sc_binary_3
is_star_class = sc_binary_4
is_star_class = sc_binary_5
is_star_class = sc_binary_6
is_star_class = sc_binary_7
is_star_class = sc_binary_8
is_star_class = sc_binary_9
is_star_class = sc_binary_10
is_star_class = sc_trinary_1
is_star_class = sc_trinary_2
is_star_class = sc_trinary_3
is_star_class = sc_trinary_4
}
}
custom_tooltip = {
fail_text = "requires_no_existing_megastructure"
#NOT = { has_any_megastructure = yes }
has_no_non_gate_megastructure = yes
}
}

placement_rules = {
planet_possible = {
custom_tooltip = {
fail_text = "must_build_around_star"
is_star = yes
}
custom_tooltip = {
fail_text = "requires_no_anomaly"
NOT = { has_anomaly = yes }
}
custom_tooltip = {
fail_text = "requires_planets_for_material"
hidden:solar_system = { any_system_planet = { NOT = { is_star = yes } } }
}
}
}

Do you have at least 5000 alloy and 300 influence?

Does the system have a starbase?
Is the survey complete?
Are there no habitable planets?
Is the star not a black hole?
Is the system not a binary/trinary?
Is there no other megastructures present?

Are you trying to build it around the star?
Are any anomalies present?
Is there at least one non-star object present?

 

[mergele]

The corporate tab is for branch offices, it's something megacorps do to other empires.

 

[bobgrey1997]

Do you have at least 5000 alloy and 300 influence?

Does the system have a starbase?
Is the survey complete?
Are there no habitable planets?
Is the star not a black hole?
Is the system not a binary/trinary?
Is there no other megastructures present?

Are you trying to build it around the star?
Are any anomalies present?
Is there at least one non-star object present?

After several hours of trying to place one in each system in the empire, I did a bit of a test:
Grabbed every science ship across the empire and sent them to a normal, unsurveyed, single-star system just outside my borders and had all of them survey it together,
After it was surveyed, I sent a construction ship out there to build an outpost Starbase. This system had a single a red-colored star, 2 molten planets (uninhabitable), and an asteroid belt with a few large asteroids. No anomalies were found in the system by the science ships.
Once the starbase was done, to ensure I had the available resources, I opened the Console and used the following commands:
alloys 1000000 (resulting in maxing out alloy stockpiles: 37,000)
influence 1000000 (resulting and making out influence: 1,000)
Resulting error: "Can not build in system with habitable worlds"
I then restarted the game with a "no megastructure limits mod" which removes the one-at-a-time limit on construction as well as most (or all) placement limits.
Resulting error: "Can not be built in binary or trinary systems"

The corporate tab is for branch offices, it's something megacorps do to other empires.

So, a corporate empire can use other empire's planet's "Corporate" tab to build their own branch offices? Does this create some kind of trade system or some sort political "uprising" to "convert" the other empire's population or something?
Apparently, one of my mods adds an "Interstellar Habitat" megastructure, a type of housing and research station offers massive Urban and "Interstellar Research" districts. Upon building one for the first time and "colonizing" it, the literal first thing that happened was an AI Megacorp built an "amusement" branch office (as some kind of "amusement park" it seems?)
Well, it looks like I will be the one using the research station to research the purpose of these "offices"

Thank you both for the replies.
I assumed rather quickly that the issues with the RingWorlds are mod-related, at least in some-part. I was mainly concerned that maybe the recent updates and/or DLC may have also affected them. So far, I have had no issues whatsoever with any other megastructure, vanilla or modded. I was just curious if anyone else has any similar issues, so thank you for sharing that.

 

[mergele]

Branch offices are strictly not harmful to the host planet. A megacorp needs a economic treaty with the host nation to establish one, it gets energy based on the planets trade value and can build up to 4 buildings. These provide a benefit to both the megacorp and the host nation, usually some jobs for the host. Exception to the above are criminal megacorps who don't need any treaty and who's buildings generate crime on the planet.

 

[kviiri]

The corporate tab is for branch offices, which are usually mutually beneficial for the corp and the host. Typically corp buildings create jobs and trade value for the host, and direct resource gain like credits to the corp.

Corps normally need a trade pact with empires to found branch offices, but Criminal Heritage corps can found offices anywhere. Their branch offices also increase crime so they're often harmful, but they also offer jobs and trade value similar to normal megacorps

 

[Longprao]

Try disabling all your mods first to see if it's the cause. I heard similar thing before about not being able to build some megastructures due to mod bug or conflicts.