how did you download and play one hundred thousand five hundred mods

also im surprised its possible to even make a world with that many mods

how do you have that many mods????

I have the same problem, but with way less mods

pro tip: don't play with that many mods. or you just don't know how worldgen works, and that a ton of mods that modify the world generation will INEVITABLY cause such issues?

can confirm portals; not sure which mod.

First of all how are you playing with 100k mods. It is literally impossible, the total amount of mods wouldnt even exceed 1k. Anyway, the funny thing with this portal issue, you need luck on the world gen. Most of the time it doesn't work, but if you get that once in a million chance that the portals spawn correctly, it will work. I know since I am currently playing with 246+ mods. The amount of time that my world gen works is very rare for the portals. If the world gen don't work in 10 minutes of portal step being done and not continuing, just know invisible errors has occurred. You wont know why cause the application is overloaded and therefore crashed.

Originally posted by Kingjack21:

First of all how are you playing with 100k mods. It is literally impossible, the total amount of mods wouldnt even exceed 1k. Anyway, the funny thing with this portal issue, you need luck on the world gen. Most of the time it doesn't work, but if you get that once in a million chance that the portals spawn correctly, it will work. I know since I am currently playing with 246+ mods. The amount of time that my world gen works is very rare for the portals. If the world gen don't work in 10 minutes of portal step being done and not continuing, just know invisible errors has occurred. You wont know why cause the application is overloaded and therefore crashed.

I found a way to solve this using World Gen Previewer and Structure helper and some cheat mod like Dragon Lense or Hero Mod (to spawn the structure wand). Optional: Quality of Terraria for moving locked chests (will explain later)

I've run at least 50 worlds to figure out that it's luck based because the spawning of Portals+Jo Shrine is within a random array, and once it decides to spawn in a certain (X, Y) coordinate, it must be there or it throws a MF tantrum. These two structures spawn as a pair, and either not spawning breaks both. Any mod that interferes with the generation of Golden Gateway and Nature Shrine from Mod Of Redemption will break your world generation, as in you can't skip the structure with World Gen Previewer. It could be a single dirt block too high for Jo Shrine, and it will break. A single cloud block and Golden Gateway will break. And ANYTHING in the invisible vertical line in-between these structures, and you can't even see your glorious world.
Enough preface, let's get to the fix:

I'm using Calamity, Remnants and Spirit mod (I know I'm greedy) which spawn structures in the sky that interfere with the Golden Gateway spawn (You'll see it as: Thinking with Portals...Golden Gateway), as it spawns randomly in the sky above the Nature Shrine (Jo Shrine) in the surface forest biome. You'll have to cancel these structures from spawning while using World Generation Previewer mod (The [R] is Remnants mod): [R] Terrain Improvement [R] Sky Islands, [R] Clouds, and [R] Aerial Garden. You should also disable the spawning of Calamity's "Planetoids", and Spirit mod's "AvianIslands" if you want 100% chance of success, sometimes you can get away with it, sometimes you don't. Can't say how many of the times it works with either, maybe 1/4 chance of fail for each? Secrets of the Shadow's Planetarium is out of the way enough, you can leave that alone.
Note: From my experience, I could never get the following structures to spawn so if you get any crap from these structures, disable them right away: "Macrocosm: Silica", [R] "Microdungeons", "Snake Cangoler" and disable ANYTHING that spawns structures near worldspawn if you are also using Remnants mod. Generated Housing's starter base, I think Secrets of the Shadows or something adds a starter house as well. Disable them.

Also if you're using Remnants and Advanced World Generation (for XL and XXL worlds) like I am, (I'm addicted, it's too late for me) you'll have to make the surface of your world as flat as possible, as close to vanilla terrain generation as possible (maybe you can get away with a little height, it's all luck based). You do this by going to Remnant's config setting and set the Terrain Amplitude value to it's lowest setting (0.5), and when generating a new world, always disable "[R] Terrain Improvement".
Also, don't let your game crash! Manage your mods to match your sitting RAM! You can easily exceed 16 gigs with an XXL world with 200+ mods! Disable non-essential, non-world gen. modifying mods!

On my first try with these instructions, with the world size of 25202 x 7202 (3X the size of a large world with 2 blocks on either side for Calamity compatibility) by not generating any structures in the sky, and with a flat surface, successfully loaded the world and the Portals from Mod of Redemption along with it.

But crap, that means that the sky has to be bare and the world superflat? Not with Structure Helper mod and a mod like Dragon Lense! By creating a new another world with just Remnants, Calamity and Spirit loaded, cheat in the Structure Wands by filtering Structure Helper in the item spawn search bar. You can now copy structures or entire biomes as a whole, except: entities and chest data. These structures save locally on your PC, and can be used with the Structure Placement wand from the same mod.
You can simply take the contents of the chest and transfer them to the placed structure in your world to populate your sky island chests or what have you. OR you can use a mod like Quality of Terraria to use their Void Wand, which allows you to take the whole chest (even if it's locked!) into the inventory of the wand, and place it just as it was somewhere else (even between worlds).
If you want to transfer entities, you'll have to spawn them manually with your cheat mod of choice and they most likely won't stay persistent; for example Mod of Redemption's Abandoned lab bosses spawn as dormant if the structure is generated naturally, but they won't if the structure is placed with the wand. And when you try to spawn the dormant boss as an entity from your cheat mod, they might be instantly in combat, and despawn on Save and Exit. That's why I thought to remove Remnant's structures before I tried to disable MoR's during generation, then enable after and place MoR's structures, it simply won't work. At least to my knowledge.

Mods used in worldgen: Calamity mod, Infernum mod, Mod of Redemption (and Spirit, Thorium, Verdant, Starlight River, Stars Above, Challenge Vaults, Secrets of the Shadows, Arbour, Macrocosm, Fractures of Penumbra, Fargo's Souls + Mutant, Better Caves, Orchid mineshaft and Devilish Arena.) I'll also try testing the WAYFAIR [1.2: Secret Stones] mod, for fun
Hope this helps anyone in need. I'll sub to the discussion for questions.