Good morning, afternoon, or night,

Me and my friend have been making a souls-like map for about a year now. I made working bosses in a 1.16.5 version of the map (as well as stuff like working "bonfire" mechanics and rolling system with animations). However, he is the builder, and accidentally updated the world to a 1.19 version over the year. In other words, he has been placidly updating it not realizing backports of full worlds are not possible.
So I devised a plan, "I'll use 1.18 litematica to make schematics of the already-existing content he made, and paste them into the 1.16.5 version!" After all, he did not use any block from anything that stemmed from 1.17-1.19 .
However, I tried this tactic, and it says "unsupported future version (6)" when I try to load the litematica schematics into the 1.16.5 version of the world.
We worked so hard on this adventure map, it even has custom music and resources! We do not want it to go all to waste now because of a mistake. Is there a way to bypass the "unsupported future version" of the schematic, even if the schematic might not technically be "complete"? We are willing to take anything at this point, and we are really desperate for some solution.

Thank you so much for reading, any help will be greatly appreciated.

Sincerely,
Ianoneshot and UndefinedTactics

Like I said in the last message, don't select Open Folder but instead just Open fro the File menu in NBTExplorer and then you can select the files. It can't open a folder in this case. I think that's meant for opening entire Minecraft worlds/saves, it won't support some arbitrary modded NBT files inside the folder (AFAIK).

You can easily change the schematics to be loadable in 1.16.5 by changing the version number in the schematic file. The change to the schematic format in 1.18 that prompted that bump in version number from 5 to 6 is very minor, and in most cases isn't even relevant, other than that the older mod versions will refuse to load schematics they don't know about.

So basically you can open the schematic file with NBTExplorer and just change the version from 6 to 5.

Get NBTExplorer from here: https://github.com/jaquadro/NBTExplorer/releases

Then just open the schematic file with it, and you will see the Version tag. Double click on it, change it to 5, hit Ok. And then click on Save from the top bar.

The latest 1.17.1 version even allows loading it directly, but that change hasn't been added to the 1.16.5 or older versions yet.

Oh cool! I try to reach the schematic files though, but they do not appear. Though I can physically see the .litematica files in the folder when I go there myself. Is something wrong?

Well the schematics I have are in a Curseforge instance, and when I see the schematics folder there is no plus sign next to it, and I cannot open the folder, perhaps I should transition these schematics to the .minecraft folder instead?

I'm not sure what you mean? When/where do you not see them? Did you open them in NBTExplorer and edit them already? Is the mod not seeing them after that, or are you not able to open them with NBTExplorer? Are you looking in the correct directory, i.e. the .minecraft/schematics/ directory of your current game instance (if you have multiple instances/profiles in different places)?

Yha I cannot do anything with the .schematics folder, it just sits there. It cannot be opened, as if NBTExplorer doesn't realize there are .litematica files in the folder or something.

Are you clicking on Open Folder in NBTExplorer? You should just click on Open and then you can select the file itself.
Or perhaps alternatively drag the schematic file from the file manager to the NBTExplorer window (not sure if that works).

I can't really open the folder at all. Let me show some pictures. It's as if the program does not recognize the .litematica folders exist at all. The first picture shows what NBTExplorer shows me, and the second is what I can see in the files myself. As you can see, the .litematica folders do exist and are there but NBTExplorer doesn't want to play nice for some reason.